Scott Marlowe wrote:
On Thu, May 15, 2008 at 11:08 AM, Shane Ambler <pgsql@sheeky.biz> wrote:
Semi Noob wrote:
My CPU is 2CPU: Intel(R) Xeon(TM) CPU 3.20GHz. Disk: disk system is
RAID-5;
Early versions of postgresql had issues with P4 HT CPU's but I believe they
have been resolved.
I am quite certain that it only related to the early P4's not the Xeon.
The real problem was with the various OS kernels not know how to treat
a HT "core" versus a real core. Linux in particular was a bad
performer with HT turned on, and pgsql made it suffer more than many
other apps for not knowing the difference. The linux kernel has known
for some time now how to treat a HT core properly.
From every thing i have read about Hyper Threading, it should be just turned off. There is so much over head to process, it killed its own performance if the application was not designed to take advantage of it.. A really cool idea that proved unfeasible at the time.
Intel is says its bringing back hyper threading for Nehalem
http://en.wikipedia.org/wiki/Nehalem_(CPU_architecture) If you can i would turn it off and see what the results are