Intel to Add TRIM Support for RAID 0

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Intel to Add TRIM Support for RAID 0

Intel's release notes for Rapid Storage Technology (RST) 11.5 Alpha version reveal that they have plans to add TRIM support for RAID 0 arrays in the next version of RST. Windows 7 and Intel's RST have supported TRIM for quite a while, but the support has always excluded RAID 0 arrays. We don't know when the RST version with TRIM will arrive but given that the Alpha version dates back to August 5th, a newer version with TRIM should be expected sooner than later.

The benefits of TRIM are obvious because the write performance of an SSD will degrade in the long run without TRIM (or good garbage collection). Here is a quick brief on what TRIM is and what it does. TRIM is a simple command that allows the OS to inform the SSD controller what files are no longer in use (i.e. have been deleted). NAND flash doesn't allow individual pages to be erased; only a block can be erased. This causes problems because without TRIM, the OS just marks the deleted files as empty space, meaning that the actual data is not erased from the drive. When you run out of free blocks, you first have to read the whole block to cache before you can erase and then re-write the block. That means instead of a simple write, the SSD has to do a read, and erase, and then a write, which is why the write speed in degraded mode is much slower. For more detailed explanation on TRIM, take a look at our The SSD Anthology article.

For users who run SSDs in RAID 0, this is great news. While RAID 0 always introduces reliability concerns, the lack of TRIM is another obstacle for many. High capacity SSDs still cost a hefty premium, and putting two smaller SSDs in RAID 0 can save you a few bucks, plus you get increased read and write speeds.

Source: Intel via StorageReview

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Yeah I may get another 120 as well.

[Roadhog]

Except it won't work until windows gets a update that will allow the trim command to be passed.

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Well considering it's Intel I am sure MS will get one out soon.

[frenchy2k1]

Originally Posted by Roadhog

Except it won't work until windows gets a update that will allow the trim command to be passed.

Wondiws ALREADY sends the TRIM command (in win7 at least).
The DRIVER cannot pass it on for a RAID Array. Intel is addressing that, so once their part is done, it will work.

[Roadhog]

Originally Posted by frenchy2k1

Wondiws ALREADY sends the TRIM command (in win7 at least).
The DRIVER cannot pass it on for a RAID Array. Intel is addressing that, so once their part is done, it will work.

No.. Windows cannot send the TRIM command to a RAID array.

[Idonno]

Originally Posted by Roadhog

No.. Windows cannot send the TRIM command to a RAID array.

Actually I do believe your wrong about that and "frenchy2k1" is correct.

Since I run two SATA II Corsair F120 SSD's in raid 0 for my OS, the lack of trim has been a major concern of mine.

Because of this I have kept abreast of all the latest developments as well as alternatives for trim.

The fact is Windows 7 has trim and my trim is turned on but it's Intel's raid controllers that cannot accept/use/implement the TRIM command.

As soon as Intel finishes addressing the SSD/Raid, TRIM issue, TRIM should work just fine with little or no additional input from Microsoft.

[Remi]

Originally Posted by Roadhog

Except it won't work until windows gets a update that will allow the trim command to be passed.

Huh? AFAIK, it always send it. There's the option to disable it, but it's on by default...

Now, if your raid driver doesn't translate it properly to be able to send it to the drives, then of course it won't reach the drives.

That translating may not be trivial to implement because, at least in stripping raid arrays, it implies to add to the controler the capability to keep track of the availability (or unavaillability) of the blocs, so that it can then use that info later when it needs to know if it's safe to send the command to a single drive...

[Idonno]

Here's a little bit of an update. If you Google "download Intel® Rapid Storage Technology 11.5.0.1109 Alpha Version" AKA "Intel RST" and previously known as "Intel Matrix RAID". In the download release notes, Notation #2 states and I quote "This release will not enable the TRIM on RAID0 feature, but it will be added in the next RST 11.5 release."

This is official TRIM/Raid 0 support for all recent Intel ICH#R southbridge chipsets 6 through present (10 at the moment) and it's coming in the very next release.

However I don't know if it will support additional raid formats but since it doesn't say probably not.