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Date: Mon, 27 Nov 2017 15:57:24 -0800
From: Andres Freund <andres@anarazel.de>
To: Scott Marlowe <scott.marlowe@gmail.com>
Cc: Don Seiler <don@seiler.us>, pgsql-performance@lists.postgresql.org
Subject: Re: Setting effective_io_concurrency in VM?
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Hi,

On 2017-11-27 11:40:19 -0700, Scott Marlowe wrote:
> tl;dr: Only way to know is to benchmark it. I'd guess that somewhere
> between 10 and 20 is going to get the best throughput but that's just
> a guess. Benchmark it and let us know!

FWIW, for SSDs my previous experiments suggest that the sweet spot is
more likely to be an order of magnitude or two bigger. Depends a bit on
your workload (including size of scans and concurrency) obviously.

Greetings,

Andres Freund