Yeb Havinga wrote:
> The rather wierd dip at 5 threads is consistent over multiple tries
I've seen that twice on 4 core systems now. The spot where there's just
one more thread than cores seems to be the worst case for cache
thrashing on a lot of these servers.
How much total RAM is in this server? Are all the slots filled? Just
filling in a spreadsheet I have here with sample configs of various
hardware.
Yeb's results look right to me now. That's what an AMD Phenom II X4 940
@ 3.00GHz should look like. It's a little faster, memory-wise, than my
older Intel Q6600 @ 2.4GHz. So they've finally caught up with that
generation of Intel's stuff. But my current desktop quad-core i860 with
hyperthreading is nearly twice as fast in terms of memory access at
every thread size. That's why I own one of them instead of a Phenom II X4.
--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.us
