I know this question has probably been asked at some point in the past, but I am trying to figure out if Windows 7 supports passing TRIM commands through RAID controllers yet.

I am trying to decide between buying a single SSD drive and utilizing TRIM or Buying two SSD drives and putting them in RAID 0 configuration

What is the fastest current configuration I can set up?

I want my development machine to be BLAZING fast.

KronoS wants an update on this:

I'm looking to see if there's an update on this, as I currently have a RAID 0 setup with two SSD drives. Will a TRIM supported SSD in RAID0 array correctly pass the TRIM command?

5 Answers 5


Edit: For some systems, Intel now supports passing the TRIM command to SSDs in RAID-0. The requirements are:

  • A 7-series motherboard (6-series chipsets are unfortunately not supported).
  • Intel's Rapid Storage Technology (RST) for RAID driver version 11.0 or greater (11.2 is the current release)
  • Windows 7 (Windows 8 support is forthcoming)

Some Intel storage controllers will pass TRIM to SSDs, when the controller is in RAID mode, and some hard drives are RAIDed. However, at the moment, the SSDs must not be in RAID in order to receive TRIM.

This will also depend on the specific SSD(s) you plan to buy. AnandTech recently compared the performance of 2 x 40GB Intel X25-V SSDs in RAID-0 to other (non-RAID) SSDs. The sequential write and (aligned) random write speeds are improved, but there are still better single-SSD options available, which will not suffer from the loss of TRIM.

Update: For Windows 7, I cannot find any evidence that SSDs in hardware or software RAID 0 will accept TRIM. Intel Rapid Storage Technology has been updated from version 9.6 to 10.1, but does not add this feature. Nevertheless, this might be possible using software RAID with btrfs (and Linux):

As I understand it, hardware RAID controllers do not pass the TRIM command to it's disks; btrfs deals with the disk directly, supports TRIM, and supports RAID. I have seen no explicit mention of being able to combine RAID and TRIM support using btrfs with independent disks so I'm asking: When btrfs is in RAID mode, does it still pass the TRIM commands to the SSD?

If TRIM is enabled then yes it should.

  • Ok, that makes sense. So if given the choice between 1 Crucial RealSSD C300 256GB or 2 Crucial RealSSD C300 128GB in RAID 0. Which is faster? Would the lack of trim be overcome by the RAID 0 speed? May 12, 2010 at 13:35
  • @John It's hard to say for sure without benchmarks, but I'd guess the RAID-0 option would be fastest, at least initially. Personally I'd prefer one larger SSD because SSDs tend to be faster the more free space that is available (and TRIM will help maintain the pool of free space over time), and because of the slight hassle that RAID adds. The sequential speeds ought to be through the roof with C300s in RAID-0 (especially with 6Gb/s SATA); but often the random read/write speeds dominate in real-life performance.
    – sblair
    May 12, 2010 at 21:38

TRIM still does not seem to be supported on RAID, whether software or hardware or level 0 or more, and it also seems that Microsoft is not to blame in this case.

From Intel Rapid Storage Technology :

Is there TRIM support for RAID configurations?

Intel® Rapid Storage Technology 9.6 supports TRIM in AHCI mode and in RAID mode for drives that are not part of a RAID volume.

A defect was filed to correct the information in the Help file that states that TRIM is supported on RAID volumes.

For the current Intel Rapid Storage Technology version 10, the article What features are supported on each I/O controller hub (ICH)? still mentions :

TRIM support in Windows 7* (in AHCI and RAID mode for drives not part of a RAID volume)

The article software RAID/LVM TRIM support on Linux confirms this fact for Linux, but offers a workaround that conserves TRIM and has the same effect as RAID-0, but without using RAID.

  • So in essence there's no support whatsoever for TRIM on any RAID configuration of SSD's. Sad. May 7, 2011 at 22:28
  • 1
    @KronoS: The only supported RAID configurations for TRIM are (1) the trivial case of one disk, or (2) when a disk is used as non-member of a RAID.
    – harrymc
    May 9, 2011 at 6:36
  • If Microsoft is not to blame, does that mean TRIM is supported for a Windows 7 software RAID-1 configuration (no firmware/hardware RAID involved)? Aug 16, 2016 at 15:11
  • @pacoverflow: I don't really know. I suppose that this will depend on your driver/disk combo.
    – harrymc
    Aug 18, 2016 at 15:09
  • 1
    @pacoverflow: That answer dates from 2014. Newer Windows may do better. See also Storage Spaces introduced in Windows 8.
    – harrymc
    Aug 18, 2016 at 20:13

As of right now: No RAID controllers I know of are passing TRIM commands down to connected SSDs.


As an aside, you can find out if trim is working by starting cmd and entering;

fsutil behavior query DisableDeleteNotify

A result of 0 indicates it is.


For TRIM to be enabled when using SSD's in a raid 0 config you need 2 things to achieve TRIM.

First and most importantly you need Intel Raid OROM 11.2 or newer (The OROM is part of your bios and can be updated via a bios update). Intel only officially supports TRIM for raid 0 SSD on its new 7 series chipset but this does not mean it can not work on older Intel chipsets ie P67/Z67 (there may be other chipsets that can have the 11.2 or newer OROM added to them), if you can find a custom/modded bios that includes the Intel Raid OROM 11.2 or newer (current is Intel RAID OROM and install the Intel Rapid Storage Technology 11.2 or newer driver (current being Intel RST you will obtain TRIM for SSD raid 0 arrays.

Here is a link to the forum I found that provides modded bios' for ASUS / ASRock (chipsets available for raid OROM update P67/Z68/Z77) motherboards - ASUS / ASRock BIOS's with updated RAID OROM(this link also contains the download link for Intel Rapid Storage Technology driver) Make sure to read the forum, it gives instructions on how to install the modded bios as well as other important information. I only have done this with Asus Sabertooth Z77 motherboard but it is the same for all the Asus Z77 motherboards, I do not have experience doing this with any other motherboard manufacturers. In order to install a modded bios you HAVE TO flash the bios via the USB Bios Flashback utility, this will require you to put the modded bios file on a usb flash drive, rename the bios file (for the Sabertooth Z77 I had to rename the bios to Z77ST.CAP, each motherboard has a specific file name and the USB Bios Flashback will not work if that file name is not exactly correct, you will not damage or break anything if you use the USB Flashback Utility with the wrong filename for the bios, it will simply not work). In order to take full advantage of the new OROM features, such as TRIM, you need to destroy and recreate your raid array, then you will need to do a fresh install of Windows 7 (Do not use an image instead of doing a fresh install). After Windows is installed and you have finished installing your drivers along with the Intel Rapid Storage Technology driver you will be all set to enjoy TRIM support on your Raid 0 SSD array.

If you have been using your SSD's in a raid array without TRIM support, I recommend that you perform a "Secure-erase" on each of the SSD drives, this is a different secure erase then what is traditional used on HHD's to completely erase data. I have personally done this to both my SSD's on my primary home computer and experienced no issues and it did return my SSD performance back to how it was when I originally installed the SSD's - HOW TO GET YOUR SSD PERFORMANCE BACK - The link will contain instructions on how to perform a secure-erase on your SSD, you will be using Parted Magic and unetbootin to put Parted Magic on a bootable USB (unetbootin is actually an incredibly useful tool because it will allow you to take ANY bootable .iso file and create a bootable USB flashdrive)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.