Re: Need help with 8.4 Performance Testing - Mailing list pgsql-performance

From Matthew Wakeling
Subject Re: Need help with 8.4 Performance Testing
Date
Msg-id alpine.DEB.1.10.0812091732130.4666@aragorn.flymine.org
Whole thread Raw
In response to Re: Need help with 8.4 Performance Testing  ("Scott Marlowe" <scott.marlowe@gmail.com>)
Responses Re: Need help with 8.4 Performance Testing
Re: Need help with 8.4 Performance Testing
List pgsql-performance
On Tue, 9 Dec 2008, Scott Marlowe wrote:
> I wonder how many hard drives it would take to be CPU bound on random
> access patterns?  About 40 to 60?  And probably 15k / SAS drives to
> boot.  Cause that's what we're looking at in the next few years where
> I work.

There's a problem with that thinking. That is, in order to exercise many
spindles, you will need to have just as many (if not more) concurrent
requests. And if you have many concurrent requests, then you can spread
them over multiple CPUs. So it's more a case of "How many hard drives PER
CPU". It also becomes a matter of whether Postgres can scale that well.

Matthew

--
 Those who do not understand Unix are condemned to reinvent it, poorly.
                -- Henry Spencer

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