Re: Intel 320 SSD info - Mailing list pgsql-performance

From David Rees
Subject Re: Intel 320 SSD info
Date
Msg-id CAHtT9RtTUYCQqwu+ve7V2hFHKAaOP534ScxgBVvqqZgWMRh23A@mail.gmail.com
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In response to Re: Intel 320 SSD info  (Andy <angelflow@yahoo.com>)
List pgsql-performance
On Wed, Aug 24, 2011 at 10:23 AM, Andy <angelflow@yahoo.com> wrote:
> According to the specs for database storage:
> "Random 4KB arites: Up to 600 IOPS"
> Is that for real? 600 IOPS is *atrociously terrible* for an SSD. Not much
> faster than mechanical disks.

Keep in mind that the 600 IOPS is over the entire disk.  performance
is much better over smaller spans - I suspect the 23,000 IOPS you
might see on the larger disks over an 8GB span are best case scenario,
though.

Moral of the story?  If you want the most performance, over-size your
SSD and "short-stroke" it.  Interesting to see that the 300/600GB
drives lose random write IOPS on the 100% span test over the smaller
disks - wonder if you limit access to the first 160GB if performance
matches the 160GB disk.  I kind of suspect that once you get to 20k+
random write IOPS over 8GB you've hit a controller limit on the SSD
since performance there reaches it's peak with the 300GB drive and the
160GB drive is less than 10% slower.

> Has anyone done any performance benchmark of 320 used as a DB storage? Is it
> really that slow?

Have the 120GB in my notebook.  Could run some tests if people are interested.

-Dave

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