Is TRIM supported on RAID 0 configurations for SSD drives in Windows 7?

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?

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If TRIM is enabled then yes it should.

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.

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.