Re: poor performance on big machine

[Freddie Cash <fjwcash+dfly@xxxxxxxxx>]

On July 30, 2007 08:34 am Francois Tigeot wrote:
> On Mon, Jul 30, 2007 at 04:58:46PM +0200, Simon 'corecode' Schubert 
wrote:
> > Matthew Dillon wrote:
> > >    Is the machine swapping?  Look at the SWAP PAGER stats with
> > > systat -vm 1.
> >
> > I did not configure a swap partition, if that's sufficient
> > information. The box has 4GB RAM (which seem not to be completely
> > usable, the kernel writes at bootup something like 512MB above 4GB
> > ignored).
>
> Some devices need to be mapped to the first 4GB of address space. You
> will need a 64-bit kernel to be able to use all your memory...

Depends on the CPU and chipset on the motherboard.

We've had great success using AMD Opterons and AMD 8100-series chipsets, 
using the software and hardware re-mapping settings in the BIOS to map 
the PCI bus/device memory regions above the 4 GB boundary.  BIOS count of 
RAM shows 5120 MB on systems with 4 GB of physical RAM.  Kernel shows 4 
GB of usable memory space.

-- 
Freddie Cash, LPIC-2 CCNT CCLP      Network Support Technician
School District 73                  (250) 377-HELP [377-4357]
fjwcash+dfly@gmail.com