Re: Postgres 8.4 memory related parameters

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
sthomas@peak6.com

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