"Andrej Ricnik-Bay" <andrej.groups@xxxxxxxxx> writes: > On 7/11/07, Andrew Sullivan <ajs@xxxxxxxxxxxxxxx> wrote: >> But notice that hyperthreading imposes its own overhead. I've not >> seen evidence that enabling hyperthreading actually helps, although I >> may have overlooked a couple of cases. > Have a look at these: > http://www.ibm.com/developerworks/linux/library/l-htl/ > http://www.2cpu.com/articles/41_6.html Conventional wisdom around here has been that HT doesn't help database performance, and that IBM link might provide a hint as to why: the only item for which they show a large loss in performance is disk I/O. Ooops. Personally I keep HT turned on on my devel machine, because I do find that recompiling Postgres is noticeably faster ("make -j4" rocks on a dual Xeon w/HT). I doubt that's the benchmark of greatest interest to the average *user* of Postgres, though. regards, tom lane
