On 08/04/2011 03:38 PM, Kevin Grittner wrote:

You're probably going to get better performance by setting that to 2
to 3 times the number of actual cores (don't county hyperthreading
for this purpose), and using a connection pooler to funnel the 600
user connections down to a smaller number of database connections.

Your note about Hyperthreading *used* to be true. I'm not sure exactly what they did to the Intel nehalem cores, but hyperthreading actually seems to be much better now. It's not a true multiplier, but our pgbench scores were 40% to 60% higher with HT enabled up to at least 5x the number of cores.

I was honestly shocked at those results, but they were consistent across multiple machines from two separate vendors.

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
stho...@peak6.com

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