Dual processor, AMD 64 machine freezing.

Andreas Braukmann braukmann at tse-online.de
Sun Feb 1 15:52:12 PST 2004

On 02/01/04 18:34:10 -0500 Haapanen, Tom wrote:

> I run a K8S Pro with dual 244s (couldn't find any 246s and the 248s were
> just too dear for me) and 2 GB ... and I started off with an Adaptec 2100S
> RAID, but had consistent panics when booting.  Apparently the aac driver
> isn't exactly 64-bit clean.

The 2100S isn't driven by aac(4) but by asr(4). The asr-driver is 
in fact not 64-bit clean (as Scott Long stated multiple times :-/).
The aac-driver is perfectly fine with the 64 bits (for me). It 
survives heavy i/o load without a hitch. I ran quite a bunch of
tests (parallel bonnie++ spreaded over multiple raid volumes and
multiple file systems, postmark, etc.) with my 2200S, 2120S and

> P.S. For best performance, I think you really want to run 4x 512 MB.
> Running with two DIMMs means either you only get 64-bit memory access (not
> 128-bit) or else you need to put both DIMMs into the CPU1 memory slots
> (which means CPU2 will have to access those through hypertransport).

Thats theory. ;-)
Since the allocators don't know about the numa-like architecture
memory would be accessed through hyptertransport (statistically)
more or less "half of the time". (CPU0 ---> HT ---> MEM1 ; 
CPU1 ---> HT ---> MEM0)


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