Be very, very careful using SSDs under your DB, whether PostgreSQL or anything else. If you don't have supercaps on your drives, you will lose data in a power l

Be very, very careful using SSDs under your DB, whether PostgreSQL or anything else. If you don't have supercaps on your drives, you will lose data in a power loss situation, even with a battery-backed RAID controller. That data loss could take the form of anything from silent corruption of a table or index, to unrecoverable filesystem loss. (Briefly, the drive's controller uses the on-board cache to accumulate writes into erase-block sized chunks before flushing to the NAND media. If you disable the on-board cache, performance drops through the floor — USB thumb drives look fast by comparison — and you shave at least an order of magnitude off the drive's lifetime.) At present, it looks like the best choice is the forthcoming Intel 710 series drives, but if you need an SSD now, their 320 series, the Sandforce controller based drives with supercaps (like the OCZ Vertex Pro models, though I wouldn't touch those with a competitor's database), or a FusionIO card are the only remotely safe options.