Testing TRIM

A firmware update gives you TRIM support, but we should probably test to make sure it's actually working.

First up, the Intel X25-M G2 with the TRIM firmware. I ran a 4KB random write test across the entire 80GB LBA space for five minutes. I ran the test again afterwards and recorded the average transfer rate for each run:

4KB Random Write, IOQ=16 Run 1 Run 2
Intel X25-M 80GB TRIM Firmware 37.9 MB/s 13.8 MB/s


As expected, performance goes down as the drive fills up. The second run is much slower than the first.

Now look at the two runs if we format the drive in between. The format under Windows 7 triggers a TRIM of all invalid data, meaning all the jibberish we generated in the first run is gone and the second run now runs at full speed:

4KB Random Write, IOQ=16 Run 1 Run 2 after Format
Intel X25-M 80GB TRIM Firmware 37.9 MB/s 38.0 MB/s


Obviously you don’t usually write a bunch of garbage to your drive then format and repeat, but we’re trying to confirm that TRIM works here; it does. Windows 7 will actually take noticeably longer to format a drive that supports TRIM and has data on it. It still completes in less than 30 seconds on these SSDs, but it's a lot longer than the few seconds it used to take before TRIM.

This confirms that TRIM works on a format, but what about if you delete a partition? To find out I created a partition on my X25-M G2, filled it with data, deleted the partition and ran my 4KB random write test across all LBAs. If deleting a partition forces TRIM I should see new-performance out of the G2:

4KB Random Write, IOQ=16 Run 1 Run 2 after Deleting Partition
Intel X25-M 80GB TRIM Firmware 37.9 MB/s 17.9 MB/s


Performance drop. Formatting a partition causes the contents to be TRIMed, but just deleting a partition doesn’t. This means if you accidentally delete a partition you can still retrieve your data, however there’s no way to go back from a format.

What about file deletion? I performed the same test. Created a partition, filled it with garbage but then deleted the garbage before deleting the partition and running my 4KB random write test. Deleting data should force a TRIM:

4KB Random Write, IOQ=16 Run 1 Run 2 after Deleting All Files
Intel X25-M 80GB TRIM Firmware 37.9 MB/s 40.4 MB/s


Indeed it does. You no longer have to worry about performance dropping over time. When you delete a file it’ll eventually be nixed on the SSD as well. Below we have the actions that will force a TRIM of data under Windows 7:

Windows 7 File Delete Partition Format Partition Delete
TRIM? Yes Yes No


Formatting your drive now actually does something. You no longer have to boot to DOS and secure erase your SSD before installing Windows, just quick format the partition before installing Windows 7.

I performed the same tests on an Indilinx MLC based SSD, this time a SuperTalent UltraDrive GX with the 1819 TRIM-enabled firmware. The results were identical:

4KB Random Write, IOQ=16 Run 1 Run 2 After Format After File Delete
SuperTalent (Indilinx) UltraDrive GX TRIM Firmware v1819 17.8 MB/s 14.1 MB/s 17.8 MB/s 17.8 MB/s


We have TRIM working on both Indilinx (from SuperTalent/OCZ) and Intel drives. Sweet.

Index Wipe When You Can’t TRIM


View All Comments

  • Anand Lal Shimpi - Monday, October 26, 2009 - link

    Thanks guys :)

    Take care,
  • jimhsu - Monday, October 26, 2009 - link

    Since I've been wondering about the free space issue, will there be a test where a drive is benchmarked vs. the amount of free space available? My guess is that the graph will be an exponential decay with the "noticeable" regime at 20% free space. Anyone cares to do this (say, at 90%, 80% ... close to zero free space)? Reply
  • Crittias - Monday, October 26, 2009 - link

    So, without TRIM, is there anything else G1 owners can do? Can I manually wipe the drive and reinstall my OS every few months? If so, should I? Reply
  • mataichi - Monday, October 26, 2009 - link

    I have the G1 and in Anand's previous SSD Anthology article he tells how to get back to 100% performance using HDDERASE.


    This is total crap that Intel is not supporting the G1.
  • DanH - Monday, October 26, 2009 - link

    Buy the G2, clone the G1 to it and sell the gen 1. Really. It is not a big loss of money to do it. Reply
  • lorax1284 - Tuesday, December 15, 2009 - link

    Basically, you suggest we pass our problem on to someone else who is less informed. It's called "Ethics". Look into it.

    Just because Intel has none doesn't mean I'm going to abandon mine.
  • klil - Monday, October 26, 2009 - link

    The only option you, a G1 owner, have to make your drive's performance back to ~100% is to do a full format of the drive. I'm pretty sure it would have to be done very frequently, each time you write 80/160GB of data to the drive... nothing else you can do, sorry =(
    Intel's wipe ultility (SSD Toolbox) only works with the G2 (for use with Windows XP/Vista) and TRIM only works with the G2 as well (for use with Windows 7-to replace the Toolbox)... =(
  • Zoomer - Monday, October 26, 2009 - link

    One can always try the Indillinx tool, after making a full backup, of course. Heck, 80GB would be less than two blu-rays. Reply
  • klil - Monday, October 26, 2009 - link

    Another great article by the one and only Anand Shimpi, king of SSDs
    So, basically Intel made a very stupid move by only allowing SSD Toolbox AND TRIM on G2 drives. I would like to know if its due to architectural changes (perhaps?), maybe you know it but can't reveal it to anyone... if I weer you i would edit out the part when you say the G3 are coming next year... or else Intel will kill you, they just lost a custumer for the G2 (me)

    But would it make sense for them to release the SATA 6 G3 drives next year if their on-board ICH10 and MCH P55 does not support it? Maybe the P57 and X68 will? Who knows?

    I'll still be waiting for those Gulftowns... =D
  • Bakkone - Monday, October 26, 2009 - link

    Don't think its that much of a secret that we will se a new generation next year. We need a version that uses Sata3 (6Gb). Reply

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