September 15, 20178 yr I have populated all of my SATA and M2 slots with drives for storage, parity and cache. I would like to continue to add a couple more 4TB reds I have, will an LSI 9207-8i provide adequate bandwidth (full 6gbps)? Are there other cards I should consider? If I do migrate away from spinners...(cache drives are SSD) is there a better option that balances present needs with future growth? The more I read, the more indecisive I become...so any experience based advice would be appreciated.
September 15, 20178 yr Actually the card you mention is well positioned for growth. You should have 830+ MB/sec usable (1000 MB/sec theoretical) bandwidth per drive. With faster SSDs about 600, this has good headroom. And that speed is with all drive run at fully speed in parallel, which is what happens in a parity check. So if SSDs would ever be your array drives, the controller would not hold you back on parity checks. The 9201-8i i only PCIe 2.0, and gives a measly 415 MB/sec usable per drive (in an x8 slot). No spinner can touch that speed. And even if you put into an x4 slot, you'd have 208 MB/sec per drive, still extremely fast for spinners, although a few might be a bit faster on the outer cylinders. I actually use a 9201-16i, 16 drives in an x8 slot. That is 208 MB/sec. But I have 2 non array drives on it, and for parity checks I have 240MB/sec per drive, more than enough to allow the parity check to proceed without being a bottleneck. I am not sure that trim runs properly on the 9201's (or the 9207's for that matter). I tried and got an error. I am not running the absolute latest and greatest firmware, so it is possible a firmware upgrade would resolve that. I run my SSDs on motherboard ports which work just fine.
September 15, 20178 yr Author I didn't even think about TRIM...cache is constantly be written/erased/overwritten ... . Since they are on native ports, I probably should check my routines. Thanks for the maths on the 9207, makes the decision process significantly easier. Seems like the no-brainer way to go (especially for just pure storage / vs overwrites) Cheers!
September 15, 20178 yr 38 minutes ago, bjp999 said: 9201's (or the 9207's for that matter) Trim doesn't work on SAS2008 controllers (9201, 9210, 9211, etc), it does work on SAS2308 controllers like the 9207.
September 15, 20178 yr Author 1 minute ago, johnnie.black said: Trim doesn't work on SAS2008 controllers (9201, 9210, 9211, etc), it does work on SAS2308 controllers like the 9207. Cheers JB.
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