Message-ID: <4E886EF2.7050207@boreham.org>
Date: Sun, 02 Oct 2011 08:02:26 -0600
From: David Boreham <david_list@boreham.org>
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To: pgsql-performance@postgresql.org
Subject: Re: Suggestions for Intel 710 SSD test
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On 10/1/2011 9:22 PM, Andy wrote:
> Do you have an Intel 320?  I'd love to see tests comparing 710 to 320 
> and see if it's worth the price premium.
>
Good question. I don't have a 320 drive today, but will probably get one 
for testing soon.

However, my conclusion based on the Intel spec documents is that the 710 
and 320 will have similar performance.
We elected to use 710 devices not for performance reasons vs the 320 but 
for the specified lifetime endurance.
The 710 series is specified at around 4k complete drive overwrites where 
the 320 is specified at only
around 100. So I see the 710 series as "like the 320 but much less 
likely to wear out". It may also have
better behavior under constant load (the white paper makes vague mention 
of different background GC
vs the non-enterprise drives).

So for our uses, the 320 series looks great except for concerns that :
a) the may wear out quite quickly, leading to extra cost to enter data 
center and pull drives, etc and the need to maintain a long-term test 
rig to determine if and when they wear out before it happens in production.
b) the GC may behave badly under constant load (leading for example to 
unexpected periods of relatively very poor performance).

The value proposition for the 710 vs. 320 for me is not performance but 
the avoidance of these two worries.