6

I have two SSDs in RAID-0 on a Windows 7, 64-bit system. Since it appears that TRIM still isn't supported with any RAID configuration of SSDs, what are some tips/workarounds that I can use?

Some things, but not limited to, that I would like to optimize are:

  • file write sizes to each disk to best match each 'block' sizes that are erased by the SSD.
  • speed of the RAID reads/writes
  • overall health of the drives
  • Settings of the RAID (i.e. stripe size)
  • any other 'tips' that might be considered for a RAID of SSD's
Community
  • 1
James Mertz
  • 26,224
  • 41
  • 111
  • 163
  • No idea, why not post them over to me and I am sure I can work some things out :) – William Hilsum May 07 '11 at 23:00
  • I'm curious about why you need two SSDs in RAID 0 in the first place. To aggregate the space for convenience? Improved sequential access? I know this really doesn't help answer your question, but my tip would be not to do this. – sblair May 08 '11 at 00:34
  • @Sblair this was done originally as a test to see if there was a significant increase in speed for a [blog post](http://blog.superuser.com/2011/03/25/the-king-of-kings-ssd-testing-part-2/). As there was, the thought was/is that one could purchase two smaller, less-expensive SSD's, then RAID them and get a faster experience cheaper. Yes, you can expect this to be blogged in the future. ;) – James Mertz May 08 '11 at 00:54

1 Answers1

4

I would suggest not using RAID0 for good SSDs. A good modern SSD is unlikely to be your bottleneck for most real-world access patterns, at least not in a way RAID-0 is going to help a lot.

Unless of course you are linking a pair of drives together this way in order to have one large volume rather than two separate ones, rather than due to speed concerns...

Some SSD controllers will take writing a block of all 0s to mean that the block is free to be TRIMed (and instead of storing the location of the block in the appropriate index store a sentinel value that means "if you are asked for this block, just return a load of 0s"). If your drives do this then occasionally writing over your free space with 0s would help, using sdelete or similar in zero-only mode. Not terribly efficient of course, and make sure your drives will react this way otherwise you will be making the situation worse rather than better.

David Spillett
  • 23,420
  • 1
  • 49
  • 69
  • The goal is to be able to have two cheaper, smaller spaced drives that give me more space but not as expensive – James Mertz May 09 '11 at 20:16
  • In that case you'll need to look into if those drives auto-trim for all-zero blocks as described above. Also make sure you have a good backup regime as you are increasing your chance of drive failure noticeably over that of a single drive configuration. – David Spillett May 09 '11 at 22:54
  • For info, [this post](http://superuser.com/questions/283590/restoring-ssd-performance-of-a-used-ssd-drive/283592#283592) describes how to "zero" an entire SSD, under Windows. – sblair May 15 '11 at 00:52
  • Raid 0 on SSD drives is a bad idea IMO. 2x the chance of data loss. – Jeff F. May 26 '11 at 17:51