Wipe When You Can’t TRIM

There’s a major problem with TRIM today. The only Windows storage drivers to support it are written by Microsoft. The Intel Matrix Storage Manager (IMSM) driver will not pass the TRIM instruction to your SSD. This means you can't use anything but the drivers that ship with Windows 7. To make matters worse, if you enable non-member RAID on an Intel motherboard the default Windows 7 driver is an older version of IMSM so TRIM won't work there either - even if you don't have a RAID array created. Your best bet is to install Windows 7 with your I/O controller in AHCI mode (for Intel chipsets) and don't install any storage drivers. Intel is working on an updated IMSM that will pass the TRIM instruction to SSDs but it won't be ready for at least a couple of months.

TRIM won't work on a RAID array.

If you want to use IMSM or if you're using Windows XP or Vista, both of which do not support TRIM, there's another option. Earlier this year Indilinx released its Wiper Tool that performs a manual TRIM on their SSDs. It works by asking the OS for a list of the free space addresses on the partition and then sending the list with instructions to TRIM down to the SSD.

The Indilinx Wiper Tool

Today Intel introduces its own manual TRIM tool as a part of the SSD Toolbox:

On any Windows OS (XP, Vista or 7) regardless of what driver you have installed, Intel's SSD Toolbox will allow you to manually TRIM your drive. Intel calls it the SSD Optimizer, which of course only works on 34nm Intel SSDs (X25-M G1 owners are out of luck unfortunately).

The Intel SSD Optimizer lets you schedule the manual TRIM operation automatically

The SSD Toolbox also gives you access to SMART and drive health data, including telling you how many writes you've performed on your SSD, and what your current flash wear level is:

Running Intel's SSD Optimizer does work as advertised. I ran the PCMark HDD suite on a clean X25-M, once more on a drive that had been well used and once more after running the SSD Optimizer:

PCMark Vantage HDD Score Clean Run Used Run After SSD Optimizer
Intel X25-M G2 160GB 35909 30354 34014


Intel's SSD Optimizer should be able to restore performance to about 95%+ of new, in this case it manages 94.7% - close enough.

Moving On: Forget About Invalid Data and Worry About Free Space

The existence of TRIM changes the way we test, something I alluded to in the SSD Relapse. Thankfully, we come prepared.

In previous articles we had to test SSDs in two conditions: new and used. The new state is just after a secure erase, the used state required us to write data to every user accessible portion of the drive first before benchmarking. The former resulted in great performance, the latter meant the SSD had to do a lot of juggling of existing data whenever it went to write. The second scenario no longer exists with TRIM. The act of formatting your drive or deleting files (and emptying the recycle bin) will TRIM invalid data.

Performance in a TRIM enabled system is now determined not by the number of invalid blocks on your SSD, but rather the amount of free space you have. I went into a deep explanation of the relationship between free space and the performance of some SSDs here.

TRIM will make sure that you don’t have to worry about your drive filling up with invalid data, but it doesn’t skirt the bigger issue: dynamic controllers see their performance improve with more free space.

My rule of thumb is to keep at least 20% free space on your drive, you can get by with less but performance tends to suffer. It doesn’t degrade by the same amount for all drives either. Some controllers are more opportunistic with free space (e.g. Intel), while others don’t seem to rely as much on free space for improved performance. Addressing performance degradation as drives fill up (with valid data) will be one of the next major advancements in SSD technology.

Testing TRIM Kingston Delivers the First Good Sub-$100 SSD (after Rebate)


View All Comments

  • dcljpc - Saturday, November 14, 2009 - link

    On that intel firmware that provide trim support but bricked people's drives, now intel said it is a problem specific to Win7 64bit. Does this mean that if you update the firmware from within Win7 64bit there could be a problem, or does it mean even if you updated the firmware in Vista or Win7 32, and then install Win7 64 on it, it could still cause a problem? Does anyone know the answer?

    I just bought a X25-M G2, I plan to use it in a new computer. Can you just update the firmware on an older computer first, and then install WIn7 64bit on it?

  • jaydops - Friday, November 13, 2009 - link

    I am looking to purchase a ssd for a Dell Studio 15 i7 with 4gb ddr3 1333ghz.

    Anand recommends Indilinx (OCZ or SuperTalent) or Intel.

    1) Are all OCZ drives good or only Vertex drives? If only Vertex then those are really expensive on newegg.

    2) Why was the Corsair P256 not recommended? It seems to have good numbers in the charts. And newegg has a reasonably priced 128gb version here: http://www.newegg.com/Product/Product.aspx?Item=N8...">http://www.newegg.com/Product/Product.aspx?Item=N8...

    3) The Dell Studio 15 has a sata connection, will that work ok with sata2 ssds?
  • crobb100 - Tuesday, November 10, 2009 - link

    No Kingston SSD for sale at NewEgg so far. Where'd it go? Reply
  • dullard - Tuesday, November 10, 2009 - link

    It is at Newegg. But it isn't at the MSRP.


    I'm considering getting it for a new Win 7 build. But are SSDs ready for prime time yet? Or should I wait a bit longer?
  • lordstryker - Monday, November 09, 2009 - link

    I was curious about the possible setup of these Kingston drives in a Raid 0 format. If they are roughly half the performance of an intel 80GB drive, it would be reasonable to think 2x of these Kingston drives would be comparable to a single Intel 80GB drive. However, I am not familiar with TRIM support on a Raid setup. Is there any info on this? Reply
  • spaceB - Monday, November 09, 2009 - link

    Hi all,

    I have a x200 Thinkpad with a SSD inside. The SSD drive is a 128GB Samsung (OEM MMCQE28G8MUP-0VAL1). I noticed that the drive becomes slower after three month of use. So I use WIN XP SP3. Is it possible to use Trim or Garbage Collection in any kind of way on this older Samsung SSD drive? The Samsung support homepage and google couldn’t answer my question.

    Big thx in anvance!


  • maraz - Wednesday, November 04, 2009 - link

    I was very interested to see results from trace-driven I/O tests. Is the AnandTech Storage Bench mentioned in this article generally available?

    Best regards,
  • Steney - Monday, November 02, 2009 - link

    What would the performance of two of these drives in a RAID 0 array be like? Would there a single 80GB drive for $170 that would be better? Reply
  • abuda - Monday, November 02, 2009 - link

    just found this stuff in mwave

    INTEL 160GB SSD G2 just US 599 with free shipping
  • kunedog - Monday, November 02, 2009 - link

    That's only $159 MORE than the predictions we got from Anand over 3 months ago:

    Wow, indeed.

    I wish Anand would acknowledge these extremely high prices and how wrong the prices in that article were (preferably in a follow-up). Especially since he is again making statements about Newegg's possible future pricing (of the Kingston).

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