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 <yebhavi...@gmail.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@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance >