Re: Turn off Hyperthreading! WAS: 60 core performance with 9.3 - Mailing list pgsql-performance

From Josh Berkus
Subject Re: Turn off Hyperthreading! WAS: 60 core performance with 9.3
Date
Msg-id 53FBB527.9030007@agliodbs.com
Whole thread Raw
In response to 60 core performance with 9.3  (Mark Kirkwood <mark.kirkwood@catalyst.net.nz>)
Responses Re: Turn off Hyperthreading! WAS: 60 core performance with 9.3
Re: Turn off Hyperthreading! WAS: 60 core performance with 9.3
List pgsql-performance
On 08/22/2014 07:02 AM, Andres Freund wrote:
> On 2014-08-21 14:02:26 -0700, Josh Berkus wrote:
>> On 08/20/2014 07:40 PM, Bruce Momjian wrote:
>>> Not sure how you can make such a blanket statement when so many people
>>> have tested and shown the benefits of hyper-threading.
>>
>> Actually, I don't know that anyone has posted the benefits of HT.
>> Link?
>
> There's definitely cases where it can help. But it's highly workload
> *and* hardware dependent.

The only cases I've seen where HT can be beneficial is when you have
large numbers of idle connections.  Then the idle connections can be
"parked" on the HT virtual cores.  However, even in this case I haven't
seen a head-to-head performance comparison.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com


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