SSD - 120GB or 2x60GB in RAID 0?

[michaelg]

Hi all,

I am thinking of installing an SSD as the boot drive for my Win 7 system. I like the specs/price of the OCZ Agility 3 120GB. But it strikes me that I may do better to buy 2 x 60GB drives and install them in a RAID 0 array (my motherboard has on-board RAID).

Obvious pro is the potential speed improvement, but there are cons too (complexity, cost, reliability etc.). Also, can anyone advise me from exerience whether there is in fact any real-world speed benefit when striping data across two high speed SSDs? Or is there some other bottleneck that means I get all the cons without any noticeable benefit?

Your comments will be much appreciated!

Rgds,

Michael

[Kie]

Hi Michael,

I too considered Raid 0 with two smaller drives, however, I believe if you stripe (Raid 0) two SSD's, you lose the TRIM feature on a lot of models, although I did read somewhere that Intel were working on this problem and may have already addressed it, I'm really not sure. I would do some research on your specific drive because if you do lose TRIM, performance on the paired drives can degrade relatively quickly. Personally, I went for the largest single drive I could afford ,which in my case was a 120 Gb Intel 520 series and although testing shows the 240 Gb version to be slighty faster, it is very pricey. My research revealed the Intel 520 range as having a relatively long life span, due to how the onboard controller deals with differing data block sizes and although they're not the fastest SSD, I went for longevity and reliability over outright speed (though it's still going to be pretty fast!). Other considerations would be your motherboard, OS, etc. so I would suggest asking Scan or do a bit of homework beforehand and then decide, as SSD technology is constantly and rapidly evolving. Google can be your best friend sometimes...

Regards, Kieron

[haelio]

Short answer: Get the biggest single SSD you can afford.

Long answer:

As the poster above mentioned, TRIM support is a bit flaky when drives are configured in RAID. There are workarounds, and this issue will be resolved soon but it's not worth the hassle in my opinion.

Furthermore, although the speed of large transfers will quicken by up to 90%, smaller transfers (4k to 16k in size) will not change much. It is changes in this sort of block size that the speed of SSDs are more apparent.

What this translates to is that while large file transfers will be faster, activities such as booting, opening applications and so on will not be much faster (if at all). Having large transfers is also of limited advantage since unless you have a similarly fast destination/source, the speed of your RAID will be limited by the device you're copying to/from. Game loading tends to be faster though (since most game engines pack their assets into a few, large files which are read like ilghtning into memory off a RAID).

Oh, and putting your drives into RAID doubles your chance of data loss, uses up a SATA slot, causes issues with Linux (although this might have changed) and a whole host of other issues

I hope this helps!

[michaelg]

Thanks to both of you, I wasn't aware of the Trim problem! Also, Haelio's comments about the performance are pretty much what I was afraid of - the gains are quite small, and the snags are significant. a 120GB it is, then!