Eric Crampton <eric@atdesk.com> writes:
> Incidently, if I turn fsync off on the SCSI machines, the performance
> absolutely soars. Of course, I don't really want to do this in
> production.
Have you tried experimenting with the WAL_SYNC_METHOD parameter?
On some kernels that can make a big difference. Not sure why
the apparent correlation to disk drive type, though.
regards, tom lane