On 18-Nov-05, at 1:07 AM, Luke Lonergan wrote:


On 11/17/05 9:17 PM, "Greg Stark" <[EMAIL PROTECTED]> wrote:

Ok, a more productive point: it's not really the size of the database that controls whether you're I/O bound or CPU bound. It's the available I/O
bandwidth versus your CPU speed.

Postgres + Any x86 CPU from 2.4GHz up to Opteron 280 is CPU bound after
110MB/s of I/O.  This is true of Postgres 7.4, 8.0 and 8.1.

A $1,000 system with one CPU and two SATA disks in a software RAID0 will perform exactly the same as a $80,000 system with 8 dual core CPUs and the world's best SCSI RAID hardware on a large database for decision support
(what the poster asked about).

Now there's an interesting line drawn in the sand. I presume you have numbers to back this up ?

This should draw some interesting posts.



- Luke

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