From: | Matthew Wakeling <matthew(at)flymine(dot)org> |
---|---|
To: | "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: Need help with 8.4 Performance Testing |
Date: | 2008-12-10 13:41:23 |
Message-ID: | alpine.DEB.1.10.0812101338490.4666@aragorn.flymine.org |
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Lists: | pgsql-performance |
On Tue, 9 Dec 2008, Scott Carey wrote:
> For what it is worth, you can roughly double to triple the iops of an Intel X-25M on pure random reads if you queue up
> multiple concurrent reads rather than serialize them. But it is not due to spindles, it is due to the latency of the
> SATA interface and the ability of the controller chip to issue reads to flash devices on different banks concurrently
> to some extent.
Spindles, banks. What's the difference? The fact is that you have multiple
"things", and queuing up requests in the controller means that more than
one at a time can be active. The X-25M is basically a RAID controller in
its own right, connected to ten flash devices.
Matthew
--
Don't worry! The world can't end today because it's already tomorrow
in Australia.
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