Intel to Add TRIM Support for RAID 0
by Kristian Vättö on November 21, 2011 2:35 AM ESTIntel'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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Roland00Address - Monday, November 21, 2011 - link
G2 drives on the other hand do have trimmooninite - Monday, November 21, 2011 - link
Linux has had support for RAID and TRIM for quite some time. The support is also agnostic to the vendor of the SSD. I have two Intel SSDs in RAID-0 and TRIM has been working fine for me.P.S. Linux also supports encryption and TRIM. It's relatively new, and not fully secure, but it exists.
Makaveli - Monday, November 21, 2011 - link
Interesting.This is a reason to buy a Second 160GB G2.
320GB of Storage with raid 0 is very tempting.
Wisq - Saturday, April 14, 2012 - link
Linux has supported TRIM with LVM for a couple years, but mdraid support is still in the process of being added, with a set of patches submitted only last month.http://comments.gmane.org/gmane.linux.kernel/12654...
LVM and mdraid use different codepaths, so there's been some confusion on this matter. But yes, I have used an LVM-striped setup (which is essentially software RAID0) since late last year, and TRIM is working.
If you're using mdraid, check your dmesg for "discard not supported, disabling". Linux won't throw an error if you ask for TRIM and you can't get it, it'll just disable it.
TheDudeFoo - Monday, November 21, 2011 - link
I have a AMD motherboard with SB850 running my SATA's - there may be a marvell controller for extra ports but the whole thing is AMD.AM I SOL?
Kristian Vättö - Tuesday, November 22, 2011 - link
At least at this point, you are SOL. AMD/Marvell may release an update, though.MajesticXII - Tuesday, November 22, 2011 - link
So will this only work on Intel SSDs or will it work for other brands that are connected to the Intel SATA controller?I ask because I have 2 128GB Crucial M4s in RAID0 on the 6Gbps Intel controller on my P8Z68.
etamin - Tuesday, November 22, 2011 - link
Is TRIM supported for RAID 1?etamin - Tuesday, November 22, 2011 - link
nvm...already discussed in other commentsXplorer4x4 - Friday, November 25, 2011 - link
Looks like this will be coming in RST 11.5 release.http://communities.intel.com/message/143346#143346