I JUST want to use a CHEAP 2-5G SSD for write ahead and binary logs. I just need 1k write ops per second with a SATA interface. Then I could drop them in cheap commodity servers and get a significant performance boost. My disks would still use software RAID 0 (at least until I replace this partitioning) but only store data.
Give me one of these for $50 to $100 and I’ll buy one with ever server.
The fsync’s required for writing to disks on INNODB can really hurt performance. My bet is that you could see an additional 5-15% performance if you don’t need to fsync (or can sync fast).
A battery backed caching RAID controller can give you the same benefits but in the $500-700 range. Hard to justify.