From: | Josh Berkus <josh(at)agliodbs(dot)com> |
---|---|
To: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Testing Sandforce SSD |
Date: | 2010-08-02 22:21:41 |
Message-ID: | 4C5744F5.3020805@agliodbs.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
> Definately - that 10% number was on the old-first hardware (the core 2
> E6600). After reading my post and the 185MBps with 18500 reads/s number
> I was a bit suspicious whether I did the tests on the new hardware with
> 4K, because 185MBps / 18500 reads/s is ~10KB / read, so I thought thats
> a lot closer to 8KB than 4KB. I checked with show block_size and it was
> 4K. Then I redid the tests on the new server with the default 8KB
> blocksize and got about 4700 tps (TPC-B/300)... 67/47 = 1.47. So it
> seems that on newer hardware, the difference is larger than 10%.
That doesn't make much sense unless there's some special advantage to a
4K blocksize with the hardware itself. Can you just do a basic
filesystem test (like Bonnie++) with a 4K vs. 8K blocksize?
Also, are you running your pgbench tests more than once, just to account
for randomizing?
--
-- Josh Berkus
PostgreSQL Experts Inc.
http://www.pgexperts.com
From | Date | Subject | |
---|---|---|---|
Next Message | Maciek Sakrejda | 2010-08-02 22:37:21 | Re: Optimizing NOT IN plans / verify rewrite |
Previous Message | Andres Freund | 2010-08-02 22:19:00 | Re: Optimizing NOT IN plans / verify rewrite |