Re: DG965ss

[lsorense@csclub.uwaterloo.ca (Lennart Sorensen)]

On Fri, Feb 01, 2008 at 09:09:23AM +0100, Dr. Helmut G. Enders wrote:
> I tried an amd64 installation on an Intel DG965SS board with 8 GByte.
> The system is very very slow (installation more than 1 day.) and
> I got corrupt files from the net (e.g. apt-get update).
> 
> I have read that this should be a Intel Bios Bug since version
> 1669 (curr: 1719), if using more than 4 GDB.

It can be slow with 4GB too.  The BIOS incorrectly sets up the MTRR
causing a bit of memory to be uncached.

> Does anyone has sucessfully installed Debian amd64 on such a motherboard?
> 
> If yes, I would like to know which BIOS Version and
> boot parameter (noacpi, etc.) you are using.

If you simply boot the kernel with mem=XXX telling it a bit less memory
than you actually have you should avoid the small chunk of slow memory.

If you have 8GB, limiting it to 7 or 7.5GB should work just fine.

Something like:
mem=7168M
should work, then after you boot and install you can check the actual
MTRR (in /proc/mtrr) to see what address is the last cached one and use
that
(so if the base for the highest entry is 8704M and size is 128M then you
would want to use mem=8832M as far as I have understood things)

It seems that essentially only intel is still getting this wrong in
their bioses, and it doesn't matter if you have 4GB or 8GB, they manage
to screw up in many cases no matter how much memory you have above the
4GB mark (which you have some of even with 4GB due to the PCI reserved
space in the 3 to 4GB area).  Everyone else seems to have clued in to
the mistake in intel's reference bios code and fixed it.

--
Len Sorensen