How I learned to stop worrying and love SSDs

When, last year, the price of decent SSD drives veered towards £1-a-gigabyte, I decided this was no longer the enviable domain of the hot-rodder. Concerns about data integrity were enough to keep me hesitant. But finally, I took the plunge. It was a revelation. MacBook Pro SSD upgrade Currently an upgrade for most laptops, …

[Doozerboy]

VM's?

If you're using a VM every day then you'll be writing a hell of a lot more than 9GB a day to disk surely?

It's for that reason that i'm not switching just yet.

Also, they're still just that little bit too expensive. At some point this summer i'll take the plunge, but it will be a small 60gb boot drive only to replace the DVD drive in my Macbook Pro.

Good point on the lack or serviceability on modern laptops though.

[Michael Kean]

Re. VMs

"If you're using a VM every day then you'll be writing a hell of a lot more than 9GB a day to disk surely?"

Not necessarily. You'll be saving just the machine state when you put it to sleep, so if it's an XP VM with 768MB RAM assigned, that's a 768MB write (if it's not compressed on the fly.) While using the VM of course it will do its own usual reads and writes.

[sT0rNG b4R3 duRiD]

What I been saying for a few years now...

First experienced an SSD on an Eee 701. Never looked back.

This, and tons of RAM to reduce swappage. Best thing you can invest in, if you like speed.

I can't say I grind hard disks, but I'm not exactly a light user either. But no failures yet on my current Eee.. I have to admit, I even have a swap file. If it dies, I'll just replace it with a new one. I reckon back up regularly and you'll be fine. It's not like you should trust magnetic media completely either.

[DF118]

Agreed

Best bang-for-buck upgrade I have made to any PC ever was adding an SSD to my current desktop.

Only drawback is I now get very frustrated waiting for my work-supplied laptop, or in fact any other machine without an SSD, to do anything.

DriveImageXML is a great option for backing up small SSDs. I have a big 1TB internal HD for data and games, plus a couple of similar capacity external drives, all of which contain a backup image of my 64GB boot drive.

[Dazed and Confused]

You've miss-understood your roll

You, or I, as a consumer exist purely to put money into the pockets of the manufactures.

Allowing us to upgrade our systems means that we do not buy new systems as fast as they need us too. If you run the standard spec on the kit you will probably be forced to upgrade within 2 years.

If they let you upgrade the memory (2 generations on my experience) and the hard drive (I seem to do this 3 times in the life of a laptop) then your might not fulfil your primary - ney Only, function for as long as 7 or even 8 years.

Where's the point in that?

How are these poor people going to make a decent living?

[DRendar]

Should have put the Joke Alert Icon on mate.

How else do the 'merkins know when you are kidding?

I am assuming it was a Yank who downvoted you - they seem to be the only people on the planet incapable of detecting satire!

[appliance5000]

my head hurts

I just ordered my Benny Hill Criterion Collection so I can be smart like you.

But seriously - i was watching a bit of this marriage thing and I'm still waiting for the punchline.

[DRendar]

Oh Dear

Benny Hill... Are you serious?

That is slapstick shite. Why when you mention British comedy do you people always jump to Benny Hill... You should be embarrassed.

[BorkedAgain]

I think it's a little unfair to join in the our-comedy-is-better-than-yours debate, but...

...did you see the US version of The Office?

Plus I have a disturbing memory of being holed up in a hotel someplace watching a dire US sitcom, with the dawning realisation that they'd taken Fawltey Towers and relocated it to Florida or something. Truly wretched. I don't think I've seen worse.

(Mind you, I no longer watch "Two Pints" otherwise I'm not sure I could make that assertion...)

[Anonymous Coward]

You're not kidding...

An SSD is a complete machine changer. I'm perfectly happily using my 2.4Ghz Q6600 machine thanks to one, and I do a lot of photographic post processing or 13meg raw files. With a load of RAM and an SSD you really don't need anything faster... Well unless you do something daft like install a new version of windows! I think I'll stick with my XP/Debian dual boot for a while yet :-)

I'd love to put one in my trusty old Thinkpad R52 because nobody makes laptops with a superbly useful 4:3 ratio 1400x1050 screen any more, but alas, the R52 has an IDE interface... *sniff*

[Ilgaz]

There must be IDE SSD

I remember seeing an IDE SSD, on mobile now so can't search effectively. Better check around.

[appliance5000]

ide ssd

Check the owc website - I think they have quite a selection.

[Duncan Macdonald]

SSD on IDE

64GB IDE SSDs are available from about £120 (Amazon). If there is enough physical room then a 44 pin IDE to SATA converter (about $20 from Cooldrives) plus a 1.8 inch SSD might be a better choice.

[Paul]

pata ssd?

They exist, you just have to know where to look! Try worldspan at span.com

[Bruno Girin]

PATA SSD

I've got a 64GB PATA (IDE) SSD in my good old trusty T42 and it works wonders! I'm not completely sure which model it is anymore but I think it's that one: http://www.kingspec.com/solid-state-disk-products/ssd-25pata-mlcs.htm

And the result is that my home T42 running Ubuntu is a lot faster than my work T410 running XP despite being 6 years older!

[Chris Miller]

Good article

But why would an SSD particularly speed up an encrypted hard drive? Surely that's mainly dependant on CPU performance?

(Closest thing to a 'confused' icon)

[The Fuzzy Wotnot]

Apple Filevault

In the case of Apple's Filevault the "encrypted drive" is a virtual disk container, once you log out it starts the clean up cycle that de-frags the container's internal contents and remove all the rubbish, that's an extremely I/O intensive task. I have sometimes sat and waited 30 mins for my machine to shut down after a heavy session of moving lots of stuff about.

[Paul]

palm misinformation

You are totally wrong about Palm, it was a pretty robust OS that had simple multitasking. Some of the 3rd party apps were flakey yes, and these could take down the OS due to the basic hardware which didn't have an MMU.

[ici.chacal]

Title

I have a few questions for those that know...

1) Does the system see an SSD exactly the same as an HDD..? (i.e can you partition an SSD and write Grub into the MBR just like a regular HDD..?)

2) We know that Windows 7 supports TRIM, but does Linux..? (or will the likes of Ubuntu and RedHat eventually grind to a halt..?)

3) Is it imperative to be aware of, and make sure you turn off, automatic defragging, or will the SSD just ignore the request..?

Ta.

[Anonymous Coward]

@ici.chacal

TRIM is not really needed on a fully encryped drive and you do not want you data on an SSD that its not fully encrypted because there is no reliable way to do a file level secure erase.

See here and the paper linked therein:

http://www.theregister.co.uk/2011/02/21/flash_drive_erasing_peril/

[Ammaross Danan]

To Answer the questions....

1) Yes and No. SSD awareness is more of an operating system feature. Windows Vista/7, newer Linux versions (don't remember the kernel version number), and yes, even MacOSX (to some extent) recognize SSDs and behave differently (ie: pass TRIM commands to the drive). As far as MBR and the like, yes, works the same.

2) Read my #1 response.

3) It's not imperative, but definitely SSD-debilitating if your OS "defrags" your SSD regularly. Debilitating, meaning reduces lifespan (unnecessary writes) and can cause your drive to run in a "dirty" state, like an unTRIMed drive.

Best bet is to run a TRIM-capable SSD and OS, or at least have garbage collection capabilities for the SSD.

A few other notes:

1) Glad the author used a V+100 Kingston drive. Their older counterparts (the SSDNow 64GB and such non-V+100 drives) are horrific performers compared to other like-priced SSDs.

2) "There's just one fly in the ointment – the age of the upgradeable computer is vanishing." - I would just like to refute this concept outright. Most PC laptops come with easy component bays for hard drives and RAM. They're even making it /easier/ to access such components. It's the world of Apple that you are seeing the "upgradable computer" vanish. They go so far as to (attempt to) require Apple-branded marked-up SSDs (via drivers) to support TRIM. This quote is from the skewed perspective of an Apple user.

[appliance5000]

I have to agree about the upgradeable thing

I replaced the HD in my g4 powerbook and about 500 screws, bits of tape, varied fragile connectors later.. It was like an episode of ER.

I think the truth is that with massive storage and memory available - and fast i/o options - there's less and less reason to go into the guts.

[Ilgaz]

win vista+ defrag ignores ssds

MS says the defrag ignores (unchecks) SSD from auto defrag and defrag itself. Just better double check yourself after installing it.

TRIM could be crucial on NTFS but not on other filesystems. I suspect it is the case as Apple doesn't hurry up with TRIM support even while they ship SSD for a long time. They will add TRIM as far as OSX 10.7 (lion).

NTFS has some interesting issues like, constant writes are almost guaranteed as it keeps updating last access etc. Not really into windows+ssd but that is what they said when I suggested ntfs on usb sticks.

[Ammaross Danan]

@Ilgaz

"NTFS has some interesting issues like, constant writes are almost guaranteed as it keeps updating last access etc. Not really into windows+ssd but that is what they said when I suggested ntfs on usb sticks."

Just a note about this comment. NTFS has "last access update" info in a file's metadata. However, WinXP can disable updating this (simple registry 0 to 1 change), and Vista/7 disables the update by default. Most of my WinXP tunings (such as this) have been made irrelevant in Win7. I use NTFS on my USB sticks simply due to the limitations of vfat.

[Greg J Preece]

I'd have one as a boot drive

But I'd still have a fast mechanical (I currently use 15k rpm SCSIs) for my code projects to be stored on. Load NetBeans from the SSD, but compile to the mechanical. Compiling something the size of our system on an SSD every day would reduce it's life, without question.

[Nexox Enigma]

Works for compiling

I tend to compile a (small) Linux distro many times a day, and doing it on an SSD makes a huge difference. Part of the procedure is removing the entire old build tree, which took 10+ minutes on a standard magnetic disk, and is now down to around 30 seconds on a (now outdated) Intel X25-M G2 SSD. The sheer number of files used during a distro compile makes the SSD totally worth it.

And I've been using SSDs for quite some time now, under all sorts of load - I can safely say that your SSD will be outdated and replaced long before it starts to fail from too many write/erase cycles from compiling. And since they're mostly immune to heat and vibration, they have certain longevity benefits over spinning disks as well.

[sT0rNG b4R3 duRiD]

Re: Compiling.

I don't do major recompiles every single day, but I completely agree with Nexox.

Your mileage may vary of course. I can and expect and am prepared for HD failure as I suspect he is. But I suspect if you truly grind hard disks, you'll probably be just as prepared for failure, so the point is probably moot.

[Joseph Bryant]

write-mostly

For desktop users, there's a nice trick you can do with (at least) Linux software raid - "write-mostly" mode. Put an SSD and an old-fashioned hard drive together in a mirrored pair (RAID1), and set the conventional drive to "write-mostly". Then, all reads happen from the SSD, but all writes are made to both disks. You get the read speed of SSD without the reliability worries. Write speed takes a hit, obviously, but, you know, it's a trade-off.

[PaulR79]

Makes sense, might get one myself

I've always been a bit conservative with drive space despite being a gamer of many years. The desktop I have only has 750GB internal space and that's on 3x 250GB drives with a 1TB external drive for backups and the laptop I use only has a 160GB drive.

I have plenty of space on all drives but the performance boost I'd get from an SSD boot drive is becoming very hard to resist. They're still just a little too expensive for me but I'm looking to upgrade in the near future so I'll probably cave then and get one.

[Jess--]

forgot a little bit of info

when ssd's do fail most (if not all of them) just lock the write capability meaning that all the data on the drive is still readable and can then easily be imaged onto a new replacement drive.

running ssd as boot drive here (with whatever HD hungry game I am playing a lot of) and a pair of 1tb drives as main storage.

[Anonymous Coward]

Depends on the type of failure

They can brick, which - from the sidelines - appears to be less of a problem with the newer gen SSDs, but your point is absolutely correct when it comes to the drive running out of write capacity (i.e. the 3 and 6 year time frames referenced in the article.

[Captain Obvious]

RIGHT.........

I have had two new SSD drives fail on me from Crucial and another brand in under two months and on one of them - NOTHING was recoverable.

While I do use SSD drive in all the laptops, and have had good luck with Kingston, they are still VERY unreliable so you had BETTER have good backups.

[RachelG]

@ici.chacal...

said: "2) We know that Windows 7 supports TRIM, but does Linux..? (or will the likes of Ubuntu and RedHat eventually grind to a halt..?)"

Professors Google and Wikipedia tell me the Linux kernel has supported TRIM since version 2.6.33 - in terms of Ubuntu releases, that's since Maverick (though the Maverick kernel is also easily installable as a backport on Lucid).

Apparently you need to specifically enable support in the filesystems you have on the SSD. There's a little howto on doing this for ext4 (the default fs in Ubuntu) here: https://sites.google.com/site/lightrush/random-1/howtoconfigureext4toenabletrimforssdsonubuntu which should also be applicable to other distros.

It doesn't indicate a way of enabling it on, say, the swap partition, but a: putting swap on ssd? are you mad? and b: if you really wanted to, with TRIM, use a swap *file* in the root filesystem instead (which is, after all, how I think most other main OSes do it these days). I suspect, given the nature of swap (fixed size file/partition randomly written into), at least on Linux, that TRIM would be of no help anyway.

I can't vouch for any of it though: I don't yet have such a SSD, though I'm thinking of getting one... and another for my macbook pro, so doing the googling here wasn't just for your benefit. :)

[Msyea2]

I must concur

I was on the verge of buying a new MBP (mine is 15" MBP 2.33 GHz Core 2 Duo, late 2007). I maxed out the RAM at 3GB ages ago and was grumbling and the concept of upgrading.

I took the plunge and I bought a 64GB SSD for my primary drive and dumped my Superdrive for a caddy plus 250GB HD (http://newmodeus.com/shop/index.php?main_page=product_info&products_id=258).

It is the best upgrade I have ever made. :-) My laptop will probably last another year or so now. Poor Apple.

[Anonymous Coward]

I'll wait a *little* bit longer

I'm waiting for the next capacity up from 256GB to become affordable. The moment they do I'll swap out the drive in my Mac.. I've been digging and I cannot reasonably zap enough to make storage smaller. I don't use Filevault because it interferes with backups, so instead I have a couple of Truecrypt archives, and anything really confidential is done under another username where indeed FV is enabled. It gets around the "one large blob" problem for Time Machine without jeopardising confidentiality if a backup gets "borrowed".

I hope the price curve is a bit like external disks - the 2TB ones now cost what 500GB did a year ago..

Thanks for the article. I have one extra question: has power use changed? I don't know how power hungry SSDs are compared to spindles.

[paul481]

Question re. size of SSD to hold OS+Apps ONLY ?

While SSD cost >>> HDD, like others, only want to add small internal SSD to laptop - to hold OS+Apps ONLY, keeping data on the 2.5" HDD.

The author suggests 64GB; - I was thinking 32GB may be more than enough to run Windows 7 + Average mix of typical user Apps. Would appreciate any advice on the minimum SSD size requirement to hold OS+Apps, and what changes to Windows settings, eg Swapfile, Defrag, to avoid uneccessary wear. Also, any links to ny indepth articles on this topic much appreciated.

[NogginTheNog]

Make it at least 64GB

Although you can install Win7 in 32GB, after a few weeks of installing apps, service pack and hotfixes, you'll be starting to feel the pinch! Not to mention any apps that then start to store data into the Program Files or ProgramData folders...

[Josh 15]

32GB SSD + Win7 = You'll Run Out Of Space Very Quickly

I did this. It was a horrible experience. I had a new PC built (Win7, 64-bit, i7 quadcore, 12GB RAM, 2TB HDD) with a 32GB SSD for the OS.

A huge mistake I was soon regretting. Within a couple of weeks, despite not installing any applications to the SSD but to my 2TB storage drive, I was seeing the red bar of doom appear beneath my SSD icon in Win7, alerting me to dwindling disk space as Windows Updates continued to fill the SSD. In the end, over a long weekend, I replaced the SSD with a 1TB SATA HDD, which now houses the OS (Win7) and I can install my applications to it quite happily.

I consider anything less than 256GB simply inadequate as a 'main' HDD for Win7. Most people don't realise just how fast their system files will balloon as Updates keeps adding and backing stuff up in the background. I will eventually buy back into SSD tech when the price of a 500GB SSD is cheap enough to make it viable - until then, I'll stick with my trusty SATA drives.

[Nick Mallard]

Pricing

"You can find a 128GB V+100 kit for under £120 on eBay"

Dammit, where man, where? :D

Prices are just going up at the moment though, making them that little bit less attractive :( Struggling to find the money for a 60/64gb unit!

Re the above comment about 32GB being enough for win7 + basic apps - I've struggled to get my existing install below 45gb, with all of the user information, page files, temp files etc on a mechanical drive. 32gb is an almost certain no.

[pj3090]

Seems crazy until you do it

I put a $350 SSD into my $450 Toshiba laptop. It sounds a bit crazy to put a hot-rod disk into a Yugo of a laptop, but the results are fantastic. It takes only 20 seconds to get to the windows login screen -- I no longer leave the machine on just because I dread the long startup. Visual studio opens and loads my last project in about 4 seconds. Photoshop, pig that it is, loads up in about 6 seconds. Everything is snappier, not to mention quieter and cooler.

[Sly]

CF-IDE adapter

This was the original consumer SSD. I have this setup in a couple of 386sx machines (yes... 386. They are that old)

Boot times reduced by at least half and I think by ~75%. Load times are stupid fast on those computers now. The CPU is the true bottleneck in those 2 computers now. The nice thing is that they are both using 1GB or smaller compactFlash cards. Those are epically cheap. Data retention isn't an issue on them since a single backup is plenty as they are purposed machines now. If a card dies... get another, load the backup and go.

This should also work with any IDE laptop ever made as long as the BIOS will see the flash card.

I would definitely love to swap out my modern PC's main drive for SSD, but they're still quite pricey for the storage size.

[RachelG]

I'm doing that too, with a 256MB CF

Running Ubuntu Maverick on a PC where all its mechanical drives form a software RAID5 array. The OS is installed there, but /boot is on the CF. Works perfectly. :-)

But my newer machine doesn't have an IDE socket...

[SSD]

32GB for windows 7 and apps.

I was desperate to have a go at an SSD being the technology whore I am, So picked up a 32GB on ebay a couple months back, replaced my laptop hdd with it and couple of months later with W7 and all my apps on it (Just the one drive on it) i've still got plenty of room. bare in mind i use this more as a quick Photoshop/office/Facebook machine and have been very conservative on which programs i have installed.

[Anonymous Coward]

Kingston says...

... some things but conveniently forgets to mention the important bits.

Write cycles are going down with the process size. For 22nm MLC it's down to 5000 or even 3000, and that's discounting write amplification and having TRIM available (and passed through the file system layer!) and so on and so forth.

Anyhow. I'll buy that SSDs are a good idea for boot disks and laptops. Doesn't work so well booting off an USB stick though, but then those are the low, slow end of the flash market.

[Bill Stewart]

SSD vs. USB Stick ?

Obviously you wouldn't use a USB stick for a laptop, because it would stick out and get broken off, but how do SSDs compare with a relatively fast USB stick. They're pretty cheap for 32GB, and that's certainly enough for a boot drive that's going to be read-mostly.

[lurker]

ssd vs usb

Although it's a simplification, an SSD could be considered to be a large number of USB sticks combined together in RAID-0 (or, alternatively, a USB stick could be viewed as an SSD with just a single channel).

SSDs are much faster on reads/writes because they have many NAND chips to which they read and write in parallel, whereas a USB stick has one or few nand chips. Typical SSDs have 8 channels meaning that they can simultaneously read and write to 8 NAND chips, USB sticks typically just have one.

Plus the controllers on SSDs are much more complex than those on simple USB sticks, which again helps with performance and provides other features such as wear levelling or (in the case of the sandforce controllers at least) on-the-fly compression.

[sT0rNG b4R3 duRiD]

USB Sticks

Look, you can use them.

But USB sticks tend to be slow, in what little experience I have had (booting alternative linux distro's off my Eee's). I'm not entirely certain what the main culprit is, the USB interface itself or the actual sticks.

The same goes for booting off SD/MMC cards.

(My pet peeve btw, are laptop/netbook manufacturers who have SD card apertures which leave some of the card sitting out - the whole card should go in and stay flushed with the casing, imho).

[Mikel]

My first essential use

OK, so I have some stake in some of this stuff I'm going to write here now. Please discount your cred factor in advance appropriately.

I work for a company that's a partner with HP. HP acquired a company, LeftHand, that did iSCSI SAN appliances. The appliances are very interesting in that they leverage the network to provide "network RAID". They also do thin provisioning, snapshots, clones, remote copies, and other things you would associate with a SAN. It's cool because the network aggregates the bandwidth of the appliances automagically. But it was software, and it still is. So HP sells a "Virtual SAN Appliance" for about $4300, that does these things - which can be useful and supports up to 10 TB of storage. You can try it for free at http://hp.com/go/tryVSA They even GIVE these virtual appliances away to folk who buy their physical appliances in some configurations. One recent customer was shocked to discover that they were licensed for 100TB of virtual SAN.

Here's the thing: in order to show people what this is, you have to set up the iSCSI SAN on a laptop. It has to have access to multiple "volumes" that it can RAID, and it you have to stand up multiple incidences so you can demonstrate management and failover. In addition to that you have to stand up a VM of whatever server OS the customer is running so you can mount volumes, grow and shrink them, and so on. You have to have a responsive client VM as well to show the management interface. A spinning disk isn't going to do here. So you can buy a $60K rack of gear (two appliances) to set on the conference table to demo how this works - or you can put an SSD in your laptop. That's a no-brainer.

In The Show, you can't count on anything you didn't bring with you. Not Internet access, not network access, not even that they have a decent display in their conference room. So you bring a compact projector and a high-end laptop to show this stuff off and you're ready not just to answer questions about technical details, but to demonstrate that you're not full of it - live and in color. SSD lets you do that and there is no substitute.

"What happens when a node dies?" "Well, let's stream a video off of the volume and you pick which node to kill and we'll see if the video stops, or even lags."

I've dragged blade clusters up onto the conference table to show the server equivalent, but it's a hassle and you're always worried about if the massive cluster will mar their fine table.

There's way too much slideware in sales presentations these days. There is no substitute for hands-on experience. You want to impress people with your storage? Tell them: here's the storage. Yank some drives. Kill your own choice of head nodes. Take some network, some links offline and see how it does your own self before you buy the darned thing. If you want power reliability, yank some cords out here and now and see how it fares. We're not afraid - just do it. If you want to sell a server, bring the damned thing to the meeting and dissect it on the table. Just let us configure it for the level of reliability you're willing to pay for and you can test it here and now.

Did I mention that I work for an HP partner and you should discount my bias thereby? I think I did. I'm not _that_ HP biased. Many but not all of these features are available in OpenFiler. OpenFiler has enterprise support options too. There are some differences but if you're committed to the best price option, OpenFiler is for you because it's free, and support can be had cheap. My company isn't yet an OpenFiler partner, but I'm working on that.

[Anonymous Coward]

Mover's blankets

I thought you said you'd come prepared?

Eh, the one with the gaffer tape in one pocket and stage tape in the other.

[Big Bear]

@Mikel

Very impressive... but I'd want to know: can it run Crysis?

[Sarah Davis]

Kingstons are great but

I replaced my desktops C drive with a 64Gb Kingston V+ last year and it's given a noticable boost to performance and boot/shut down times. I now use SSD's as C in all new builds (mostly A/V and Studio Workstations using W7pro).

[Robert Carnegie]

Points

I think you can disable NTFS maintaining "last time this file was read" = rewriting folder records on a volume, but I forget how.

I've been advised that Windows minimum page file should be 300 MB on the boot/system volume (C:), at least to receive a system dump from a crash, but you can put more page files on other partitions. I suspect that if you partition an SSD then internally it will still use the entire volume for wear levelling and successive writes of the same logical disk locations, but if you're using a disk backup program that doesn't know not to back up the page file (some do), it may pay off that it's small or absent in your critical partition.

And I assume that a disk with e.g. 80% full of data that is never updated will mostly* not involve that 80% of space in wear levelling, and will pound the 20% of empty or volatile space over and over again, instead. Basically then it's the "fridge is more efficient when full / empty" question. Is there a case for buying an over-large SSD to protect you against its inevitable failure? Given the price premium, probably not. Just be fanatical about backups.

* I assume also that it's still the case that if a file that doesn't get updated is stored next to a file that frequently is, most likely they will both be physically written over and over again, because flash memory isn't designed to be written a sector at a time (512 bytes), like hard disks. So both files are picked up and then written back to flash, but below the level of operation that recognises files.

[Anonymous Coward]

Counterpoints

Do you actually use that system crashdump, ever? If not, no point in saving crashdumps.

And, er, flash can be written just fine per sector*, but can only be erased as a cluster of sectors. But wear leveling is there to fix that among other things by lying through its teeth about what sector you're actually referring to, so it really oughtn't be a problem on modern SSDs. And yes, static data will hog the wear leveling space. A good SSD will come with some extra "hidden" scratch space to make up for that a bit. If you're paranoid, by all means, get a much bigger drive to provide more scratch space.

* 512 bytes wasn't the law for very early hard drives either, btw. And is slowly becoming too impractical so various devices offer various sizes again.

[Robert Carnegie]

"Clusters" are pretty big, relatively?

I thought you could only write Flash by erasing it first, or something? Like, set all the bits to 0, then set the bits that you want? So it amounts to the same thing.

Just so we can agree, these aren't exactly the "clusters" that FAT and NTFS volume formatting - well, not NTFS - used until they switched the name to "allocation unit", although they're similar?

The article seems to assert that technically a lot of your data is stored in multiple copies across the flash memory although you probably can't get it back unless you're a government spy agency, or a big commercial spy agency... erasing only happens when the de-allocated memory is used for a new write?

And, the likes of SD cards and USB memory sticks probably aren't nearly as clever as this? I mean, retail products of those classes are typically sold without any indicator of speed or performance, let alone reliability. Even the Windows ReadyBoost logo, an actual speed mark, is seldom seen. I use these in video recording devices and it's pretty annoying. Busbi USB3 sticks however seem to make a respectable performance claim, even for USB2 use, so that might be my next purchase in that sector. That or a proper SSD in a USB enclosure.

I read recently, probably here or at The Inquirer, about how laughably easy it evidently is - there's probably kits - to build and sell a small flash memory device that claims to be a large one but of course discards a lot of data instead of storing it. These are sold ofiten on eBay, but not exclusively, and sometimes by innocent middlemen such as if your local computer dealer shops on eBay for component bargains. An SSD-shaped box that turns out to contain a USB flash stick must have been a horrifying discovery.

[Anonymous Coward]

A bit late, but anyway.

You can only write in sector sized chunks (say, 4k bytes) and you can only overwrite, as in write again after there's been written to it, after you've erased that spot. And you can only erase in cluster sized chunks (perhaps 128k bytes). If there's already some data written you'd have to read all that first, erase, and write again later. That extra writing is called "write amplification" and ssd controllers work hard to minimise it. "TRIM" is a way for the OS to tell the ssd controller what sectors have been deleted well in advance of actually needing to write them again, giving more wiggle room to keep performance up. Indeed, usb sticks and such don't have fancy controllers (yet?). You don't get very good performance from them either.

Writing clears the space for more writing though that's not always "set to all 0s"; in NOR flash it's actually "set to all 1s" and writing means knocking 1s over so that the data on disk matches what's written. You could perhaps still try and knock them all down to 0 after the last erase.

And no, SSD sector- and cluster sizes are not necessarily your file system's sector and cluster sizes. The *BSDs' UFS for example allocates data in "blocks" of, say, 16kB, but to optimise space use a bit the last odd chunk of data can be stored in a "fragment" instead, typically one eight the size of a block. _There_, the "0.5% fragmentation" might see during the boot-up sequence means that 0.5% of all the data sits in fragments instead of blocks. This is quite spectacularly different from what "fragmentation" in a FAT-based filesystem means. Where, predictably, a single byte file takes an entire "FAT cluster", say 32kB.

NTFS has the right of it to call it an "allocation unit"; FAT clusters are called that because they're some (power-of-two-)multiple of the underlying storage's sector size, though I don't know how exactly it handles sector sizes other than 512 bytes. Quite a few things have or had "512 bytes" assumptions built-in in unlikely places.

All those terms are similar in that they refer to chunks of storage space in various sizes. They're quite dissimilar in that they don't necessarily have anything to do with each other at all.

[Synonymous Howard]

Stopped me upgrading

That is to say putting an SSD in an MBP stopped me upgrading to an Air (that and the lack of keyboard backlighting on an Air). As well as the speed increase the MBP is now almost completely silent (tiny bit of fan noise if I push the CPU for long periods). I only bought a 64Gb one as most of my data is on the LAN anyway and I'm a bit of a cheapskate.

[The Fuzzy Wotnot]

Pricey

They seem like the perfect answer for getting a bit more life out of my laptop but at £350+ for 256GB that's a little pricey for a laptop I paid £600 for 2 years ago. If I can hang on for another 12 months, then hopefully they will have the consumer 1TB SSDs out and this will start to push the 256GB down to more reasonable prices.

I'd love one but just to expensive to justify right now.

[vlc]

Spread the wear more thinly?

you mentioned that it uses techniques for spreading the wear.... does that imply that higher capacity drives last proportionately longer?

[Disco]

Dual Drive Laptop?

It's been a while since I looked but I was really into the idea of a dual drive SDD (OS)/ HDD (Data) setup for my next laptop but I've had a real job finding any suitable, current, machines. Is there anything out there that warrants a recommendation?

[sT0rNG b4R3 duRiD]

Dual Drive laptop

This is tricky.

What I consider a laptop is anything 13 inches or less that doesn't burn your bollox off.

For me, this really means, something like a netbook or at worst, something like an Air or an Asus U31. Or even the low end Apple Macbook, although these can get a little hot, at least the ones I've had do.

Now some of the 15 or 17's have dual drive bays, this may be your best bet. But they're really not lappies in the sense of my definition, more like desktop replacements.

I have an SSD in my Eee with an SD/MMC card for more (portable) storage.

[SpottedCow]

Have your cake and eat it too...

Some of the new Lenovo ThinkPad and Dell Latitudes based on Sandy Bridge architecture now have another option. The slot that supports a mobile broadband card now supports the mSATA standard too, making it possible to install an SSD in that slot.

I put an 80GB Intel "Soda Creek" SSD in that slot (since I won't ever use a mobile broadband card) with my new ThinkPad T420. It's functioning as my boot drive, with a Western Digital Scorpio Black 500GB SATA drive to store my data. I've redirected all my user profile folders (docs, pictures, video, etc.) to the platter drive, as well as anything with high write patterns (e.g., browser cache) and getting the best of both worlds.

[Frank Bough]

Macbook Air has no user upgradeable HDD?

Wow, and I thought it was flash based...

[Anonymous Coward]

Not just new machines

I have a 4GB Compact Flash card inside my Amiga 1200 instead of a standard IDE drive. It flies! Workbench takes about 4 seconds to fully load. I can see how larger cards could be used in laptops.

[David Fetrow]

Hybrid SSD/magnetic Drives Available

I put a recent Momentus hybrid drive in a MacBook: It had (I believe) 4G (?) of SSD and 250GB of magnetic. It was the same size and cost about $50 more than pure magnetic.

That machine is only used web email and video so I don't know if it would improve VMs but it halved the boot time (after the first boot, which was slower, as the drive figured out what to put in SSD) and Safari loads faster.

These are different from the rarely seen SSD hybrids introduced for Vista: The intelligence is in the diskdrive electronics rather than the OS so it works fine with MacOS (and pretty much any other OS I expect).

Pure SSD would have been faster still but there was enough intelligence and SSD on the drive to make a notable performance difference without cutting storage. The $50 premium seemed well worth it; especially in a single drive machine.

[Anonymous Coward]

Math fail: closer to 100 year lifetime, not 3

Assuming a conservative 5000 cycle/cell lifetime and 64 GB drive size, you can write 320000 GB before the drive fails (at least from a flash memory failure).

If you write 9 GB/day on workdays, the drive will last 136 years. Not the 3 mentioned in the article. Simple math.

Lots of people are stressing out about wearing out their SSDs, with NTFS this and VM that. Look at the numbers and chill out. You could probably grow old and die before writing that much data.

[Anonymous Coward]

Article is a mess

Sorry Andrew, I generally like your articles but this one is a mess. Why waste 1.5 pages talking about how great more RAM is in an article about SSDs? The point about Windows "housekeeping" (whatever that is) and Palm reset buttons is completely incomprehensible. Also, you'd rather do a 15 second cold boot now instead of waking your computer from sleep in 1-2 seconds with all your program state intact?!?! And you certainly don't need a mysterious "enterprise" SSD for higher performance, just look for one with an Intel or Sandforce controller, they don't cost much more than the Kingstons. And with an SSD, Preview opens in a tiny fraction of a second. What version of Photoshop do you own that does this?! And if this article is supposedly about you being afraid of SSDs, why did you explain your concerns about their reliability (unfounded) in a couple paragraphs clear at the end of the article?