From: | Dave Crooke <dcrooke(at)gmail(dot)com> |
---|---|
To: | Yeb Havinga <yebhavinga(at)gmail(dot)com> |
Cc: | Francisco Reyes <lists(at)stringsutils(dot)com>, Pgsql performance <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: 10K vs 15k rpm for analytics |
Date: | 2010-03-02 21:05:07 |
Message-ID: | ca24673e1003021305p7014202dj3c5a2ff575ce4e83@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
Seconded .... these days even a single 5400rpm SATA drive can muster almost
100MB/sec on a sequential read.
The benefit of 15K rpm drives is seen when you have a lot of small, random
accesses from a working set that is too big to cache .... the extra
rotational speed translates to an average reduction of about 1ms on a random
seek and read from the media.
Cheers
Dave
On Tue, Mar 2, 2010 at 2:51 PM, Yeb Havinga <yebhavinga(at)gmail(dot)com> wrote:
> Francisco Reyes wrote:
>
>> Anyone has any experience doing analytics with postgres. In particular if
>> 10K rpm drives are good enough vs using 15K rpm, over 24 drives. Price
>> difference is $3,000.
>>
>> Rarely ever have more than 2 or 3 connections to the machine.
>>
>> So far from what I have seen throughput is more important than TPS for the
>> queries we do. Usually we end up doing sequential scans to do
>> summaries/aggregates.
>>
>> With 24 drives it'll probably be the controller that is the limiting
> factor of bandwidth. Our HP SAN controller with 28 15K drives delivers
> 170MB/s at maximum with raid 0 and about 155MB/s with raid 1+0. So I'd go
> for the 10K drives and put the saved money towards the controller (or maybe
> more than one controller).
>
> regards,
> Yeb Havinga
>
>
> --
> Sent via pgsql-performance mailing list (pgsql-performance(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-performance
>
From | Date | Subject | |
---|---|---|---|
Next Message | Scott Marlowe | 2010-03-02 21:12:12 | Re: 10K vs 15k rpm for analytics |
Previous Message | Greg Smith | 2010-03-02 21:03:20 | Re: 10K vs 15k rpm for analytics |