Re: Do I have a hardware or a software problem?

Actually most of low-end SSDs don't do write caching, they do not have enough ram for that. Sandforce for example.

Or, worse, some of them do limited write caching but don't protect their write cache from power loss. Instant data corruption!

I would be extremely reluctant to use low-end SSDs for a database server.

If we are talking about dedicated machine for database with ssd drives, why would anybody don't by hardware raid for about 500-700$?

I'd want to consider whether the same money is better spent on faster, higher quality SSDs with their own fast write caches.

-- Craig Ringer                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services