Pragmatic 12: Pages Blocks Planes Die Bank Device

10 February, 2014


John and Ben discuss SSDs, data transfer bottlenecks and the evolution of PC data storage architectures.

Transcript available
This is pragmatic weekly discussion shall contemplating the practical application of technology exploring the real-world trade-offs will get a grid ideas are transformed into products and services that can change our lives nothing is as simple as it seems I'm Ben Alexander amicable strategy 800 doing very good Ben he'd excellent our thank youse are special for you to live business and chat room and dive straight in festival again thank youse to everyone from much for an afternoon still getting lots of great feedback thanks guys thank you everybody really appreciated arm I also have a main minor correction designing a synapse 11 and I said at one point it was 1.44 MW power station which is really tiny note looks exactly 1.44 GW so whatsoever anyway arm special thanks are against the listeners of email me directly got a few more this week and arm I will have a backlog I apologise for begetting publicly that next week arm panel for iTunes reviews are three from Canada and one from Portugal just conical as well and is are so thank you to Wah Berkowitz protected them practically new 1234 are JVC_PT and Cajun on rails which is critical so again much appreciated and are glad you're enjoying the show so much so thank you for those are just an update on Dante distortion is migrating across systemic it's going well I am getting close but not quite there yet are low this week I finally transferred my domain from go daddy to hover singular but want to do for quite some time so why am hopefully then the updated site will be up next week and then now you feel free to let me know and think about what some men are you hands this is minimalist for since the very beginning and I've been pushing this our topic back for a while but I know that you're very keen for me to talk about this one so far would you like to tell everyone will talk about retirement necessities today yes we are and what are the reasons I wanted to about SST's is because I've always been absolutely fascinated by the idea of completely no moving parts are as long as it was you growing up seeing hard drives and floppy disks and everything that it was one of those things that some I thought one of those bill out of RAM and of course that I learnt that obviously remedies Barry on Bob, blah and actually I was kid are one of my friends are fathers was a bit of a computer geek and he built his own RM desks like literally a circuit board I would buy sockets on it and RAM and they are only estimates of a RAM drive there was very cool are I have no idea what the specs were how much memory it was noted it looked really cool arm but the idea though I could look at it as well is not something upper level domain but no to the geek in me it was just that is awesome that the idea of a completely solid-state drive has always fascinated me so our business is that SST is a become the quickest way to transform your computer and my a lot of people using is now with SST's but there's a lot of little things about SST is that not always as these are created equal and I guess that's why want to talk about is because there is as this is a she quite a bit to cover in order to get your head around which SST is the right one for me of and you so as I start by soliciting some boundaries on this can talk about hard drives not really arm because it's not really the point of it from the point of it all I have to give it history so that we basically know where we going in my understand why we are where we are so semi-one of those are bit of history lesson there so in any case arm the argument SST over hard drives and is there's a whole bunch of really good reason so let's start with there's a whole bunch of our analysis and reports and stuff that's been done by all the different companies one ones I found close resting numbers from those I will corroborate most them in a given three. LB 90% less phase of solid-state drives is as hard drives less money because no moving parts 44% increase in speed for tasks such as waking from sleep rebooting operating an average of 12°C cooler power savings up to 70% for some models there much stronger physically and can handle much larger shock and vibration physical impact on a hard drive SST's generate no vibration and hence they create no noise compared to a hard drive so whirring sound nothing and SST's are also lighter than hard drives so irrespective of all the advantages of speed this heck of a lot of really good reasons to go to SST's mass wife asked solid-state drives are in a practically every every laptop every performance laptop you'll find okay so first of all our gossamer pot bottlenecks and is the are the problem is that you've got data in one place and you want to get to another place so you're starting your CPU quite .81 and we are to point B us hard drives going to bed in between point A and point B through a pipe and that if the pipe is not fast enough then that is essentially a bottleneck which means that your data wall logo no quicker than the minimum speed in that system which is a pain in the neck so a lot of the stories of longer stuff that SST's is all about the gradual iterative removal of all these bottlenecks have existed in computing design sites start by talking about serial and parallel so initially parallel one all the early battles with transferring data between point A and point B the idea was simple you could transmit more bits at once I see you have one wife reach Brittany group 816 3260 form together these beholden wide ribbon tables and you could clock through 60 bit 64-bit is a time well early buses 816 economic you could literally clog all that through at the same source be reviewed and serially was now you have to send one after the other one after the other and would take quite a lot longer for a given our clock speed so that was what everything originally was all parallel release all the high the highly data rates are databases for all parallel so originally the ATA standard arm stands for advanced technology attachment and what it was the originally it was called ATH stomped on ATA but it was actually up parallel ATA is what I came to call it once our serial ATA or silo came about size of retrospectively renamed it to parallel ATA which is a bit weird so West little car that 986 and they release the integrated Drive electronic interface allows IDE and was first in compact PCs that year spec included not just the bus back but also the drive controls physically on the hard drive itself was the first of the time so essentially an ISA bus which is the industry standard architecture design stands for is greater 9081 by IBM but all the ATA was initially really was a an extension of the ice of us it really did very little in the way of modifying the signal or anything existed was it was just like the thing on the motherboard but now connected through a card are to the hard drive is all our dry control cards factor anyway arm but these ideas are course of the controller on the dry Sony to go to the motherboard essentially to ribbon cable straight drive anyway so originally the ATA bus started out of our 16 MB per second and then progressed to 33 6600 that maxed out hundred 33 was 16-bit parallel architecture however one of the things that they began to discover in computing was that parallels Nehring is cracked up to be because when you've got multiple cables running next to each other with talk about this previously with our capacitive and inductive coupling as a signal goes up and down my positive to negative or from 05 and back again as you're sending bits voltage pulses along they represent the bits what happens is that actually creates a very small magnetic field that magnetic field couples the next wire which covers the next wire and all the wires then start to basically message other up you think of each of them is a transmission line and a transmission line with a variable impedance so the outside was of a different impedance to the inside ones because inside ones are surrounded by more wires so it meant is to get this skewing effect whereby the bits in the middle will arrive later than the bits of the outside so if you imagine all the bits being sent on 16 wires at one point and a monotonic of the other cable the ones in the middle of lagging behind the ones on the outside and this clock skew was a big problem because it meant was your essentially we would reach a point where the skew was so bad every time you clock them said read the data on a 16-bit she would know not know what data were lax to belong to because this clock skew was too bad to parallel turned out to be not the best way to go because once the once switching technology for transistors and MOSFETs and someone got that point where you could go faster and faster and faster it became the losing proposition because of all of the out the issues with the with coupling between the cables source will be counterintuitive it's funny it started out as is serial it was slow and I went parallel to go faster and I went back to serial to go faster again which is kind of strange but that is the way it worked out anyway so a little bit more about the ATA arm they developed the drive interface standard called a ATAPI which is the best technology attachment packet interface and that then led to cider which was their attempts to overcome the parallel problem parallel our bus problem with all of its clock skew my stuff sales crown 2003 and start at 1.5 our meagre Megan the megabits per second and then to 3 and six so you can represent those however in megabytes which is the more commonly awaits referred to hundred 92 384 768 MB per second the problem is is a serial interface which means that's in a serial interface you Wanna you Wanna make sure that you don't have a separate clock so I do is I actually do what I call it be 10 B arm encoding and what that does is that it represents a bit signal in a word a petabyte sorry by 10 minutes and hence the number of symbols makes it such that after so many successive bites you're guaranteed to have a recoverable clock signal so in effect the clock is encoded with its own data so you encode the data when you send it you decoded the other end any decode the clock at the same time you're decoding the data which means that you have no skew issue you have no synchronising problem it's beautiful it works really well and as a result though the raw data rate is not the actual data rate is that extra two bits every single byte takes up space and you lose that so that ends up being hundred 50 MB per second 300 and 600 and that's the start of 123 respectively so that's how we end up with with cider and the speeds that you'll often hear quoted the difference for the different interfaces are also talking about now about PCI express and it may not make sense yet but it will become clear later so start a Mount Isa so moving on from that I was Liza Gazza said 981 IBM came out without as a bus interconnection arm for Beyoncé pure memory and initially was a bit moved on to being 16 bit parallel parts it can only handle a maximum of six devices and in its initial our sides is final evolution faster than ever got was 8 MB a second which by modern standards is tragically slow they were if you remember PCs from that era in the 80s and early 90s they were the long black arm white black plastic sockets to jealousy those in your travels here the Amarillo's one year i.e. filled a lot for it with some with computers back at that point in yer arm I was very highly sceptical when PCI came out that was the next one IOW the dull bit shorter but they will be the white not quite as wide high-density whitetail sockets so PCI stood first as for other peripheral component interface in the its paralysed Thai architecture like I so however it was created in 1993 and it progressed from 32-bit 64-bit starting out hundred and 33 MB per second and finishing at 533 MB per second which is pretty zippy there are a couple of little ones that happened along the way NPC land are one of them was cynical AGP which was sorta brief that was the advanced graphics port and that was released on 96 it was designed to be a point-to-point link not technically a bus and it was designed specifically for a graphics card hence the name advanced graphics port but are it was 32 bits and is inevitably when PCI express came out it, died which is probably a good thing is that I have on the else like a brownish or orange coloured connector open not sure I do remember ashes while ago and they put them on the motherboard are slightly offset the PCI slot so that she could actually accidentally put Robert Hardiman still annoying memory have one customer was in the last PC before my Mac was Axa going through my box of old stuff is well can I been a gig I keep stuff because you never know how my mom I need AGP graphics today and I found AGP graphics card and what I call and looking around the room and on there is no computer is a little fit horse Hector I thought about keeping it and I thought no time there was all arranged one point another one that i.e. arm when I was a nicely forgot about this but someone is doing research for this episode I came across Michael remember that briefly and it was PCI X come across the email is a weird one it was server side so what I did is a PCI bus and I just doubled the width of and it was essentially only a year and implementing service that I have a sort which is why I only came across it once and they have is honking great big long cards and is go inevitably in the end it was a very me staying in an up dying which is again a good thing I think and eventually PCI express came about and how lawyer so PCI express is the motherboard equivalent of cider and other words it was the transition from the parallel architecture to the serial architecture serial is just better for high speeds so PCI express it's actually not technically a bus… People will be confused by this it's not actually bus because on a bus you've got a whole bunch of our address lines and each of the cars is given address on all the data travels in the same bus from talking on the bus you can't talk on the bus blah blah blah and it's a shared it's a shared access media muscle biases however PCI express isn't it slight AGP it's a point-to-point connection so imagine that you've got a bunch of channels all they call lanes and you can then connect the carding and also look kindly on 92 lanes and the controls they can have five and six or whatever and so then that point-to-point link is established and excellent talks on nominal stalks on them is no addressing the matter simply negotiation and then that's it so there's been quite a site technically has been the re-but the fourth one is imminent so there is so call for versions since it was created in 2004 so are each of the versions is essentially defines well for all I care about talk about today anyway by the data rate for a given line so the 16 lines in a PCI express version 1 each lane is to 50 MB as Ahmed was a second version to ease a 500 MB a second version 3 is 985 MB a second and a couple years ago I started release motherboards that support that and version 4 is 1969 MB second best bit of a screamer but that's that's coming up soon so the idea is a card can say I want one only one lane I need to lazily four lanes whatever and cohesively accumulate those data rates to get all the bandwidth that you need for whatever your application might be in at the end of the tournament buses still make sense imminent so please bear with me okay so now you talk about arm memory obviously because little man SSD's okay so breaking down memory into two sets of buckets so the first bucket all category when a court is the restraint volatile memory nonvolatile memory simply realised when data can be retained without power a.k.a. electricity applied to don't ring I go to Steph about history of RAM and ROM ID rimless. Not really want all that arm not not this time anyway in general essentially arm ROM is read-only memory meaning that you cannot modify and random access well actually it fantastic can't be modified without difficulty arm perhaps a better way of putting it and a nice as a fluffy but I'll talk about a bit more a minute are whereas RAM is random access memory but random access memory is not the opposite of ROM ran a matter simply means you can access different past the memory randomly whenever you feel like that either spittle and that bit of another bit and all completing all other place solely randomly maximum like so I swam so as said seller finally saying that read-only is it difficult to so difficult to write to but there is of course the traditional standard ROM and it was burnt in a factory sealed up in a box and insert into a socket and it was the end of you never got an update on and remember changing out with this updated firmware on the panel printer a long time ago the icicle dweller previously and you literally had to pull the thing out and put the new firmware in and make sure the pins to bend the pens Coffey bent the pen are as a because these things are shipped from the state somewhere in Australia and gave you bend pen is it only bend pen on most things if you try and untended it it netted like it almost snaps off the first time you try and straighten it as the material is made out of just doesn't this doesn't arm can't handle dislocations the worker back and forth of snaps first time is terrible and isolated the next one are ex-con of ROM was an erasable programmable read-only memory which was called a nephron or any profit on site and from and what they had as I have is usually a small quartz window and their lease was to grow the top and usually on the sticker you have some kind of warning if you remove this then you'll lose everything in the world Linda, think sometimes also put the version number of the family to write you that sort of thing whatever and is in order to actually raise these things you would take the sticker off and exposed ultraviolet light pros they had their little ROM caucus law ultraviolet arm thingies are biker you pretty ROM and then take the split off slight shot Turner line on and it was a little black box with a light together have come across any of those button arm of the pros had those are when I was mucking around that arm EPROM is originally are before us are moving onto the EEPROM's disorder next are I actually didn't have an ultraviolet light source except the son and what what I did in some of the early projects that I was because I was into one electronics was cleared and used to build kits from our local electronics store, like RadioShack Arbuckle Dick Smith Electronics filing was icy not working that later on so why am anyway and is when you download the firmware you have to start with a clean ROM so PII actually took the bill sticker but often put out on the windowsill and what of the sun to raise it because it took a hell of a lot longer and one time I did it I didn't live long enough and I got back and before you wrote to it you had a prior program routine you did run to check to make sure thing was actually black Michael FFFF and knew it wasn't so then you have to go back and start all over again just to be sure they always wondering about lesson the sun long enough long enough asked painful tone very painful anyway so the particular physics effect ultimately much but just mention it is called hot carrier injection and that's important later I will get back to that and that's the way you would reprogram them as a wiki article link to view students very interesting but you bit to physically further while were going today so EEPROMs which is what most people start to think of my think of our programmable ROMs and they are electrically erasable programmable read-only memories so EEPROMs much better trust that mouthful is no mucking around ultraviolet light which is great hell of a lot better developed by Intel in 1978 but I did not actually come across one until RG's would have been 90 to 93 I think it is because things are built in EEPROM are our brothers it was EPROM and EEPROM program which is a kit from the Smiths and argued light of the Dos software it was a black box with a with a socket on top and you are simply input your ROM and Eve EEPROM and their and or does it would apply a high voltage to the chips and essentially bite by bite winter would wipe out those statements and you could write to it and are in central ROM problem was our they were expensive and honestly not quite slow in terms of RAM say really never really took off that much say what I rather they raise and write data using a field electronics emissions feel free look them up as well is also called Fallon nought time tumbling which is much cooler sounding as a wiki article read up if you like okay now were almost about read talk about flash soul this revolution there are essentially two paths that silicon went there was the bipolar junction transistor B JT or there was the field effect transistor will affect and fence are the ones I want talk about me and I have thought about IGT's before insulated gate bipolar junction transistors and they are used predominantly for our power switching so you bipolar transistors are eventually evolved IGT's and which is of a hybrid between FETs and B JT is a mass that greater power electronics but where only really interested in the facts so the fence have a common channel and then visit us think of it like a groove rounding outside it puts our end and died silicon around the P-channel and by applying a voltage to that that generates animal feels electric field and that field rules essentially choke off the fly think of it like a pipe with water going through it and you squeeze your hand on the pipe that stops the water from flowing through after a long period time from her chair as well but still that's essentially the principal the problem with that is that they leak and was happily coming the voltage you apply will eventually inject or it will extract electrons that try to go through the channel so I only do as it insulates between the gate and the actual channel so why do as a depositor metal oxide semiconductor our silicon dioxide which confounds it weird because of things estimated a silicon but anyway silicon dioxide acts as an insulator and insights that gays from the channel quite effectively and they call that a MOSFET so flash memory is technically in EEPROM but the mechanism itself isn't exactly the same as lexical rewriting its content modified MOSFET so if you can imagine a MOSFET with us with a single gate and flash memory has an additional gate that they call the floating gate so we would normally call the gate and a MOSFET in the AM flash is referred to as the control gate so all this actually was invented a while ago was actually very back in 1980 and the name was coined in a number mangle his name are by ADR Gelman from Toshiba is me called our show she resuming and he noted that the process of raising flash was just like using a flash from a camera the funny thing is though despite failure Toshiba invented flash originally wasn't them it was Intel that actually mass-produce the first commercial flash memory that was in 1988 so was actually quite a big gap before anyone actually went and took the idea and industrially produced at all this time of course EEPROMs come along and now they were still had their issues but but that was the first time it was Bill and it was built arm they called it nor nor flashes in a knot or gate a normal gait to North flash are again use the same in O'Fallon nought time tumbling for erasure and it uses hot carrier injection for programming so NSS and essentially the UV effect that we are talking about for arm one should we want to programming that hot carrier injection is actually what sets the state of the of your floating gate which is what stores the data in the flash so North flash is more expensive so they cannot with a different kind of flash called man flash I don't want to go down into too much detail as to the exact differences again I've got some really good leases and accent e.g. Herald article that is really interesting it's a good read and I highly recommend you check it out are our courses cover Wikipedia entries as well so the relative physics the difference between nine and please do but don't want go on Oral-B go here for hours so are now flash uses different from local tunnel injection tunnel release out for writing and erasing respectively and is it is essentially are much cheaper way to build and is its although it is not as fast but still arm is axial is another article on Tom's hardware about entitled should you upgrade to an SSD describes a lot of want talk about in pretty easy to understand language so also recommend checking that out so flash memory therefore for the two categories manned or nor and is wine or as fast as it gives full bite by bite access essentially it's what you would call a are not as is nonvolatile Ramos out would be categorised as great as a replacement for firmware but because it's so expensive and is the memory that is retained and it needs to be refreshed are more regularly than Amanda Gatewood are it's some it's not really useful for is a hard drive replacement but man's although Natalie gives you block by block access it can be packed at a much higher density and has about 10 times lifespan sought cheaper and is therefore man is far more analogous to a hard drive with sectors that go with Nan you've got blocks aside is more analogous to hard drives is to ramp and therefore is not really a good replacement for RAM but it's a great replacement hard drives so this two kinds single level cells and multilevel sales SLC is MLC's which we did briefly touch on our in episode nine I think it was art was haematoma flash as a backup our method size is not about again here we go are which is essentially there is the multilevel cell is that you get two layers that are one and the multi-bit and therefore you can quadruple a data density so you got two bits per gate and therefore to spread is forcing four options of forced different states for that particular cell in terms of our longevity are it's about 10 years and again this is something I took a previously sorry was episode 78 my apologies was 97 are and that that particular time flash is hereafter what I say flash that is now on talk about about manned man flash okay is present and most most mostly MLC because MLC is the one that everyone must use as a stripper and still pretty fast so SLC is is fast the stress of this fast and MLC writing but are MLC reads faster not quite to 3 times as fast this is carried by the difficulty in reading the multiple bits of the layers at once because you've your sensory two layers of information out of oneself so that leads to more requirements for error correction is the more errorprone is alien and error correction in that's fine but honestly you take performance if the doing so bottom line is you boil all the way arm SLC is faster cost more than a sway generally don't cease much okay so whereabouts mechanism is inevitably the more you read and write to a block flash of the grades its ability to contain that charged in the floating gate and after a certain period of time that title simply dissipate alligator data will be lost so which point the controller on the SSD will flag is bad and ill than not use any more so the controller tries arm to manage the read/write cycles evenly across the entire SSD they call that process where levelling financial each little cell gets the same amount of usage as every other cell part of that sounds arm discreetly wrestle sees is that big day also average about 10 times more light on MLC's but so SLC's will have about sale… Pick a number say hundred thousand cycles while obviously being 10 times are better are MLC's want to come in about 10,000 but having said that they did get to alarmed if you had an 8 GB man's MLC SSD if you keep up with all the acronyms are that says got standard 4006 blocks and it then it's gonna take 75 years of average usage to actually kill it so it's not like it's that big a deal by comply to muscular men kill every single cell and it so you know it's not as big deals might think but still arm right, the better are so SSD is just like IDR drives have two components they have the controller on the drive and they have the memory itself which is no flash memory chips or integrated circuits and is people often refer to people from further controllers as the chipset sales they want what chipset stresses the running and is those chipsets need to deal with address translation because computers are expecting to see a logical block addressing structure that you get a hard drive across sectors year usually followed four bytes more recently 4 kB but the point is it it's it needs to mimic to some extent translate between the structure of the SSD's memory and what the operators mixed but is expecting to see so anyway are the predominant popular chipsets are tend to be the same force once Micron Intel and samsara so there are others of course is nonexhaustive list but that's just those the big white sand force is probably the most well-known so I guess the Intel ones are as well so to principles behind speed on SSD controllers are data striping which is essentially like RAID zero sand force also push data compression now by using both of those techniques and basin level striping and compression as possible obviously that varies based on the kind of data you're compressing so text or compress a couple are better than images and video well generally so nicely give you quite a wide variance in performance when you between different solid-state drives and that is Lisa some confusion surrounding well you know which is better which is faster and under what circumstances are fast so an interesting aside with RAID zero is there RAID zero does not actually give twice the performance the idea of data striping is and I'm encouraged look up if you offer me whether the idea is you have two drives and you put a stripper data on each drive and therefore will access it are you simply grab a piece from about one half from one drive and the other half you get from our drive and you combine them together and then your bum so you can access time of of say 10 ms which is actually atrocious to speaking a number 10 ms on one you to Temasek and dries well if you're gonna grab half from each then you intend milliseconds or grab a whole lot rosier trying grab a whole lot one drive will take you 20 more seconds and is ludicrous to mean milliseconds is terrible but still the point is that it doesn't then theory you would think I was twice the drives therefore beyond get twice performance that's not true at all because you gotta combine the data between them and there's other issues you got a deal with it's not that simple it's more like about 20 to 50% and that's hotly debated because it varies based on the strip size the usage part of the drive was of data you are transferring some data lends itself to it like larger files for example your see bigger games so you RAID zero is not the perfect solution some people don't really don't like it anyway so circling back to sand force again that was found in 2006 x 2 very clever gentleman Alex Knapp got knackered Naqvi and Rado are done near lack any I think a spouse apologies I five mangled those names but anyway they released their first driving 2009 and then after a few years they sold themselves out to LSI and I was 90,002 so there drive controls have a very very popular and undergone some respite working for them and they used by also to the OCs and our IWC transcend Kingston and assess a few there's a lot more so samples is very very popular and with good reason is a very good chipset are the controls are designed Ferdinand MLC flashlight less than their business model was they want to be like Intel by Intel say here is the CPU you put on your computer and put Intel inside bad scores your Apple in which case you don't put stickers on your dam laptops because it looks terrible resulting it does anyway so that was sent forces business models and still is far as I'm aware are there was there was some problems though not sure if you came across this one at all Ben but I actually did I had a friend had a driver is affected by this survey had issues with their firmware hour for a couple of versions where they were getting some corruption in the drives that you limit as a few years ago now remember reading about and I think is likely wouldn't get unlucky of blood and how many SSD's at the time and date the first SSDI I was actually what I bought my MacBook Aaron are it's not seen for some controller anyway I'll get that later on but some yummy day they had issues and they suffered a little bit of arm as the brand perception damage I guess you'd say now so I guess it was very unfortunate for them and I'm not sure that play a part in their moving to LSI also was a result of our signup white IO fire exact timing of that but I do know that they had some issues those are kind of important thing to get right anyway are the thing about the sand force control as part of their algorithms to get the best possible where out of your drives and the best performance at your drives is that they do something called over provisioning which you when I first are looking SSD's I was to marry someone why he these drives 480 meg while a 240 meg 60 magazine you know that everything is gonna be in base to settle be like 64 128 to 56 x 12 where is this other stuff nine and it comes back to that the sand force control in the samples control over provisions in other words it takes away some of our space our hourly use our space so you may be buying 64 GB regional U 64 GB because they can keep about 7% and a callout over provisioning does is that space handles background tasks that they use for things like our garbage collection for example, to little things that they do I say little things that complicated again you are good Wikipedia articles again in the shallows I encourage you to listen to reason if you're still exactly what they do so it is very cool and is what ends up though ferocity is really a 60 dealer space for gig is gone we just never get to see it at the available drive level is billable which sucks and and motor a lot of the other controllers don't do that I'd like to add size the sand force from SN forcing okay maybe had a bustling courtroom what trim tries to do is it tries to essentially follows the rules of the operating system level to reduce the amount of wear and tear on SSD specifically because the warrant mechanism SSD is Yeadon Thurber in writing to inform drive all the time so the idea was trim was that it was a way to reduce that specifically SSD's and for quite a while our OS X OS X sorrow did not support that Annie was 10 R 10.6.8 I think it was the broader in the initial trim support I don't have it in front of me so was it wasn't CRS was that's five full five years ago, truth is that there were SSD is around before then so the transport is a big deal again not to die too much into trim but suffice to say it's not it's the idea is its operating system plus an SSD working together in a sense to a common standard in order to reduce the wear and tear on SSD so it's very important but same time every operators and now I think pretty much as an Windows had sent staff for age something even Vista may have had arm if not deftly in seven otherwise in a pretty poor performance on SSD is just like you on hard drives is our casing so that was a memory net about a thing so set burst of data and assorted buffers at and write it in a nice orderly fashion packed together and buys itself some time so that buffering that casing are also helps doesn't help as much as I hard drive though because the read/write because it is so much faster on flash they are on a hard drive so still a little bit helps so again is lots of really good articles on the subject styling to quite a few of them and if you really into this you will learn more about than now then there's deftly some good stuff there is a out as a conference a few years ago and it was really good there's a couple one said it was the our presentation by Ryan Fisher senior application engineer at Micron technology imaginary micrometre controller manufacturers and designers and that it was surrounding flash performance that I gonna learn all about multi-planes interleaving in multichannel techniques than feel free to read up on our don't really want to go to that level of detail there's not a lot in that another slide deck in that list as well by a guy called Robert Sykes from OCs and technology good information in it although I will admit it's fully not the best format slide deck a was sort of wise things where they arm in other slide decks where there are a page full of text arm that was one of them but some information is good so if you just overlook the slight formatting them it's still good stuff anyway so the structure and SSDI's talk about the structure of the memory now as we talk about controllers ad nauseam some odometer soda flash memory itself when I quote these figures I am I quote the user data area as the first figure and the second area is what I call span data for the want of a better name I guess since I click on the better name a map anyway and a spare data is used for parity and full-page health purposes and does not and never counts towards the actual storage title and when you actually look on these are flight/trip chips and drives and time you will not see it quoted most of the time majority drives I've seen you don't see a split you to see the first number the user data that's all the user cares about so that I care about spent I seen set but there so I started the smallest possible unit and work our way up to the biggest so there are six levels that they talk about those levels are pages blocks planes died bank device digital at start with par with pages pages H alliance +512 bytes is the smallest readable unit Sony reading from a flash of the smallest unit you can read a block is essentially a page times by somewhere between hundred and 2856 pages that brings you up to about one meg 1 MB +64 kB Basa smallest writable unit because we talk about the MLC/smallest writable unit so when you're writing a block you the pages are written sequentially but essentially written as a block so that page size will vary from hundred 28 to 26 is used while the other betting on the overall size of the design of the chip so planes are essentially blocks times 490's 4096 so that will then take you up to 4 GB plaster 56 MB of spare data and as a plane so what you do is your you will have all this laid out in a plane in the in the silicon something like a physical layer now when you actually put those that silicon in a die then you have more than one layer like a pancake so you can have single-layer layer of course single plane but typically it is to some more recent ones are gone for was always an even number because it's just the same kind of you base to progression 1248 1632 Bolívar so we got one we got to some of got for our dye level Sunday at the dye level effectively now you're talking about a chip so that is physically now you're holding your hand a chip in a die and that's up to about say in this example anyway 8 GB +512 MB of spare data from that point then we started selling them on the banks so it's okay I'm now going to have let Sadie arm two of these so gave 2×8 amount to 16 GB so you got those two banks are so +1 GB of of spare data keeps creeping up and then you are at the top level the device level I now buying a physical box that I now put my computer or physical car so the stock standard in SSD's it's basically ADR and SSD and hard drives clothing same dimensions as a 2 1/2 inch hard drive I love OWC and they make a whole bunch of different drives no we are not sponsored by IWC but hey this is the greater an example to the Mercury lecture 6G and 60 private or probe 60 which arose per site look at the 480 GB models $380 US and $448 US respectively Lazarus between standard and the pro now his eyesight in the blurb while any OWC SSD will provide significant faster performance in a traditional hard drive the ABC Mercury extreme prior to is optimised to handle incompressible file types like those used by audiovideo photography professionals for the fastest performance available tomorrow/the marketing just what the hell is it actually mean so how do they do it why they do it so the differences between the two really intensive practical terms as they going to give you an extra two years warrior pro and the higher incompressible data rate so that his work is will be disingenuous is they quote the maximum that the maximum speeds for these drives as 556 MB a second after read and follow 23 MB is taken for right and they are the pro and the standard model are they actually have very very similar numbers so there there plus my specifiable 10 MB second there essentially the same ring) but then I have another one incompressible data and in the incompressible data it's a massive difference is that the pro model is twice as fast as the standard model this whole incompressible data thing this is where I say it gets a little bit disingenuous this is using a sand force are SF 2251 controller and is just for the sake of completeness the 1632 gig Intel are micron feet for 25 nm asynchronous NAND ICs and they all combine on the site three interface but the samples controller is the is the point so the problem is that because it relies on compression in order to reach the peak data rates that you see 556 MB a second for example if you give us something that in incompressible all you is highly compressed already than what it can do it can't account get blood out of a stone you can't capacity more than is already compresses the limit so essentially it's never gonna reach that top speed on the standard model anyway you get higher than that is by having a high spec flash chip on it which is what the pro version has so what you end up with is essentially a view is a different kind of NAND flash memory values toggle NAND instead of the asynchronous NAND and again as a with Peter over going to those subtle differences but the point is that Solomon is much faster are an essentially are whatsoever about then went about excelsior in a minute but is more expensive so you know that's where the extra what is an extra $68 comes from is from the other toggle NAND's I do find it quite frustrating because when you look out on the surface of the two drives look pretty similar but once she read a bit further down and you realise how the samples controller is actually get some of their performance claims and performance boosts it sort of to me it's a little bit in I've off in II don't think it's fair there are certain conditions if you're transiting a bunch of text files year rental bullets at Shaw you anything else and will not perform anywhere near as well and that's that's what sucks so something to be aware of this, talk about is the one my own laptop that I'm our recording on right now and that is my 2012 MacBook Air finish MacBook Air our love this laptop best level of aligned and anyhow it has a 56 gig solid-state drive and they notice that every six gig and they know what what why what you know because you in listening and paying attention it doesn't have a sand force controller and exhibit deadly to be 240 gig know it has a Samsung R8 30 series controller the actual part number if you really care and if we don't hear is anyway is an S for LJ 204X01 article I told you that 20 nm integrated circuit so this particular one has a whole bunch of different arm mechanisms that don't include eating up that's our 7% percent force does and still performs relatively well but I suspect it's in my having other issues with longevity perhaps but in no that's are more difficult to qualify so design choice I guess samples made now the particular model I've got is star has some 21 nm MLC 32 gig gigabytes are ICs are eight of them in total and all that is on a very narrow are very narrow circuit board with an M starter connector at mobile starter and operates a site of three speeds this particular drive arm and also justice for the sake of completeness the actual chip that is a canine PFG why 8U7B map particular ship with that control of the 830 series controller actually gets 447 MB per second read 401 MB per second right now if you really really really really need every last little bit of speed and I guess the way side are perhaps suggest you probably don't but you if you did then IWC also sell a model for the aura pro 60 and that will fit in a MacBook Air and it'll give you an extra 350 maker megabytes a second read an extra hundred megawatts second right speed however arm dinner it is sand forcing your quite as much space you guys at 7% and most people knock I see a benefit from that unless you're upgrading from hundred 28 gig SSD tool for an 80 gig SSD I know why bother I wouldn't so apples SSD they supply with their MacBook Air's and their MacBook Pros are actually pretty good and not coming once that the kind they're quite decent so it's it's the sort of thing that you know once again reaffirms my belief that I why likeable stuff is that they tend to put in our better better quality and better performing stuff all right the last will talk about and then will be done is kind of gone past me now and what I mean is that where once it was an option I had the and I had 2009 the Hayley quad core macro which chewed through an enormous amount of power and for the sake of electricity bill kinda decided it was time to sell it will bit salad but no actually paid off our military development and significant anyway it had PCI express bus around Watauga PCI express and this is why all the drives up until this point have all been dealing on-site of three which is maximum 600 MB a second so all the previous drives we had them the top speed you're gonna get arm was for the ERI to BC Mercury Electra pro and was around 560 MB a second so was getting dangerously close that sale three limit so what's the point of having SSD the controller can then transfer data fast and that if you stuck on site three you never realise any further any faster because you've got that modelling what we talked about the beginning of symbolic problem so how do you then get rid of the bottle I can get more speed out of an SSD and the answer is you stop using cider and you start using PCI express directly instead and that's exactly what IWC did then and not to stand is not a driver they call the river drive you may have heard of and these are PCI express harm solid-state drives and is the funny thing is I told I talked about are my friend's father who put together that that RAM drive and the funny thing is putting slots of of memory cards into a PC kinda resembles what he builds years ago minutest ocelot fast and a lot bigger than the storage so the owner BC Mercury excelsior or E2 now subbed into practical that 480 GB model so the same size as the Electra the Electra arm the primal was $448 while for 80 Gb is $630 the same amount of space so why the extra money well it's PCI express version 2.0 is a two lane card subunits are PCI express version 22 lane card we know that therefore gives a maximum bandwidth in our discard of a thousand megabytes a second which means we broken past the 600 MB a second limit of cider three so we now fully able flexor muscles but more speed it uses our sand force SF 22 E2 controllers on each daughter was as to daughter boards operating in RAID zero and I said I call them daughter boards so that's a year that it article daughter boards by attending Leslie's because they call them blades arm yes it sounds, cooler but anyway, blades anyway so each of these door harpist almost comparable to each of these blades has its own sand force controller operating in RAID zero and what they quote for the ends there is a difference between Stalybridge and Ivybridge but just stick with Sandy Bridge primary right speed 780 MB a second in it that she read speed and 763 MB a second right speed so that is well above the previously electros and definitely the year the MacBook Air is solid-state drive pursuit and the only reason you can do that is because it's on PCI PCI express so essentially scientist lost my place are the next point aura that is a valid according to arm IWC at 820 MB per second are as to eliminate our now everything on this bed is on fire yet that said you you're right it did I say a 20 that if you dig as the Ivybridge figure rate the reason I didn't say that is because arm when you put them into a Mac Pro then you would only get the arm decided a meg I fear that a longer quote that for PCs and again this comes back to Lila vitamin C would come on there's a little bit of BS: right is it that the maximum speed depends on the architecture of the Intel CPU is attached so NPC lands that something to be aware of any could realise the 820 in Mac land honestly that the Mac Pro is now a trashcan right so you can't fit PCI express and there in a standard card form factor anymore so you're out of luck right if you've got your constricted to the small format to the specific card balance referring to here is no longer an option buying a brand-new marrow the only reason I'm mentioning it is because I poured over the detail on this and I was obsessing about his life I am so many of these things and I make my nail Mac Pro absolutely burn some JPEG's just like on their website but no one didn't do that why because the power power bill and that was the end of that dream range of figures expands downright a man and think of the JPEG's minimum can't be a pleasant feeling so anyhow arm that's the unfortunately as was the Mac Pro no longer supports that which is a shame but you know if you got a PC or older Mac promptly people still do then you know these things would absolutely blow anything else out of the water the flash on is MLC/24 nm Toshiba it's toll might MLC then just like you are the pro version of the Electra now I tried very hard to find a high-resolution photo of these blades but I said we couldn't find one that showed the exact ship identifier I want to go down that level and check out the most likely options based on the research that I did and I decisively sent my tavern I might know what it maybe does matter much but hey were either there is 428 gig Toshiba arm flash ICs in the top layer all these 864 DIC is so eager for the top and fauna bottom not sure which it is it's more likely the 8 x 64 gig either way arm essentially it has filed into a mega storage which when you take it over provisioning you down for an 80 MJ quoted in terms of speed if you do the maths it's actually a 40% improvement due to the RAID zero configuration slightly more if you're on Ivy bites you that mail there may be some specific performance tweaking that they've done on that are in order to achieve that because you generate phraseology for between 20 and 50% from visibly varies any depends the data is being written and all those provisions I said before you know to pick pick a number any number they've picked that their numbers were down 40% well yeah I think that you would realise that in some circumstances yes but perhaps not not all the time and is our asset I considered is going into USB flash drives but to be asked arm I been going for more than an hour and I for the will might be a good point to draw a line under it there happy to come back and talk about our USB flash drives but seriously it's a variation on a theme different package and obviously USB and USB three all have different restrictions in terms of their bandwidths but how the SST is attached within them are very similar so galvanised by soft and SST now Ben Ari harnesses the one in the he can never have to can I have a fusion drive on my Mac the MacBook was also a fusion drive that is a fascinating development is not in Haiti find a fusion drive refinance significantly faster than the starter arm whilst I want from my little opposite what is areas there are dog slow think 4200 rpm drive that came with the Mac 756 being as long as owners are things is another adventure put something called pro arm ourselves merely sold and jumping to the SST from is like, and others is a completely different machine this is what it should have banned from factory then went in on Savannah went back, slowed down by going to the fusion drive but nicely other than occasional arm I'll have weird slowdowns trained to our final file on the desk just occasional extra directories arm and finder will disorder else that there are only to spend the 20s I can resell for a fun I can figure out what's going on an uneven of that directly because of the fusion rabbit other than that I have only seen a big performance that arm but it is a cover same stories were retiring about with with the students exhibiting low tax files implied programming projects like power was on everything is maiden day now and that really made a difference by you beyond that it so it can be hard to tell exactly what's gone on here also in two minds eye I am going to get a Mac mini once I think I may have mentioned this before when they upgraded to the young 5000 series graphics are and of course the next CPUs so the arm as well are you CPUs and I EAI's town still waiting Apple come on anyway arm she can do it are I know that our Clinton and I have talked about is often suggestions is that they going to release 1/2 height Mac Pro and that's the Mac mini arm which I really wish they do because I would be supremely cool but some EAI currency happening really on the short term but maybe one day arm if they are released they are an AirPort Express and AirPort Express express sorrow and AirPort Extreme looks like a arm cheese I know like you know those some square drink coasters and you have like 200 stacked up on and has available rights is so strange but anyhow arm so you only get one I get the Mac mini others get with the as you say the stock standard Chiba's hard drive and I was sort of thinking what do I leave it as it comes down to 1 TB now I think and Wally was 1 TB or do I get onto my class I put in one of these Saddam Electra or equivalent arm SST's and then do I go fusion authority separate and it seems to me based on what you said and what a lot of people set as the main effusions I want to go and and haven't had any counsel is nothing more than a thing is really nothing's gone wrong at part arm it is a lot of Michelangelo denies it is enough to do to set it up as my guess is really tricky if you're comfortable to outline whichever honest into the star's pod casts absolutely you are twilight is your friend Artesia member even when battle happened right side arm the old McGuinness 50 hours 10 there is a commandline what's going on is the Mac is it's all over road and you look at all the things that we we can do all the really cool house we can do through the commandline had ever lived without very very handy anyway sizes Mac Ramdas's was Dos box now arm but anyway and use as they can about what you're saying an article losing Doug about the Libby all-round desks and an carnival looks like things are becoming now 37 signals the base camp guys beaded are swivel or walk-through of their hardware architecture arm Megan doesn't have a use of caching at the database and canopy Julia and the guard these are the servers of the third-party put these things together but there just is gigantic gum sent letters is gigantic round round desks plus huge SSD storage and this just that's all there for is making incredibly optimised single calls and new mama had been significant at a want to show notice sounds really interesting now it's some is open the news recently I think regarding our general still happily skilling on more more RAM and SST's and the parlour they are actually put on the blog was just an honour to 50 or 60 memory sticks to sitting on a hunter also Mrs Erbakan call Elwood Molinos actually I'm what when I went to the IRA about my MacBook as SST but it really it really was mine day for me and I have a computer at work as you work they they corporations are gonna give you a laptop you must have a laptop and so they give you this this Dell or HP piece of crap and it's just shot tested it's a new level of shocking and I and arm anyway so this thing is so tragically slow that some is just a nice fire my laptop and it's it's running and is to 3 minutes later others it finally comes up with a login prompt on the work laptop wow disorder sisterly images sensory as Lorraine it hundred 64 MB around the block for $12,000 whale which is okay then allows the business with articles about Mrs from 2012 arm this essentially that here that the scanner discount architectures are now affordable and invisible and you can search engine that we are delaying applications yeah and severe I know I have heard some people talking about having a yard a unified memory someone one big blob is to dress things wherever you liken it orders works as a separation between them are between hard drive in and in memory and that's a whole other discussion but that is that is fascinating idea it's in any case i.e. arm down enough to adjust and are actually though I think that unless it finished having osteo and how others define our finer bark oracles for that so that was interesting and that the related allotted down so I you want on my brothers you can find John on Twitter at John Geagea to the same adapter that trigger John state that distortion do come and if you want to send an email you can send it to China tucked distortion do come and then Alexandria can reach me on Twitter at Felix the farm should follow our pragmatic show on Twitter decision announcements and other related materials thanks Leslie and Ron Baxter thank you Ben and thanks everyone especially thanks to the guys like chattering thanks: delayingďż˝
Duration 1 hour, 9 minutes and 50 seconds Direct Download

Show Notes

Bus Communication:




Premium supporters have access to ad-free, early released episodes with a full back-catalogues of previous episodes


Ben Alexander

Ben Alexander

Ben created and runs and Fiat Lux

John Chidgey

John Chidgey

John is an Electrical, Instrumentation and Control Systems Engineer, software developer, podcaster, vocal actor and runs TechDistortion and the Engineered Network. John is a Chartered Professional Engineer in both Electrical Engineering and Information, Telecommunications and Electronics Engineering (ITEE) and a semi-regular conference speaker.

John has produced and appeared on many podcasts including Pragmatic and Causality and is available for hire for Vocal Acting or advertising. He has experience and interest in HMI Design, Alarm Management, Cyber-security and Root Cause Analysis.

You can find him on the Fediverse and on Twitter.