Re: Poor performance on seq scan

Lazlo,

On 9/12/06 2:49 PM, "Laszlo Nagy" <gandalf(at)designaproduct(dot)biz> wrote:

> I'm using FreeBSD, and not just because it dynamically alters the
> priority of long running processes. :-)

Understood.

Linux and FreeBSD often share some driver technology.

I have had extremely bad performance historically with onboard SATA chipsets
on Linux. The one exception has been with the Intel based chipsets (not the
CPU, the I/O chipset).

It is very likely that you are having problems with the driver for the
chipset.

Are you running RAID1 in hardware? If so, turn it off and see what the
performance is. The onboard hardware RAID is worse than useless, it
actually slows the I/O down.

If you want RAID with onboard chipsets, use software RAID, or buy an adapter
from 3Ware or Areca for $200.

- Luke