Subject: Re: cool AMD
To: Patrick Welche <prlw1@newn.cam.ac.uk>
From: Michal 'hramrach' Suchanek <hramrach@centrum.cz>
List: port-i386
Date: 07/20/2005 00:42:04
On Tue, Jul 19, 2005 at 05:40:03PM +0100, Patrick Welche wrote:
> Basically, can I fry an Athlon while running NetBSD, or is there some
> hardware safety cut-out if the temperature rises too much?
> 
> Longer version: I have an AMD Athlon XP 2200+ plugged into an Asus
> A7V600-X motherboard. The CPU should run at 1800MHz and cooks at
> 85C. The computer is dual booting - Windows 98 & NetBSD. Under
> Windows, which runs asus superprobe and friends, the whole computer
> closes down after a while.  I watch the temperature in superprobe
> go up to about 70 C. Under NetBSD, I can happily run for a few
> hours (admittedly, that was console only, without any heavy
> calculating). All this is when running at 900MHz, so I thought it
> should be cool. (The fan, as supplied with the CPU, is happily
> spinning at 3900 revs/min and the inside of the case is at 35C.)
> 
> The fundamental question I'm trying to answer here is, is this a
> silly Windows programme problem, or is the chip really overheating?

Athlons do not have the feature that exists in Intel CPUs that just
halts them when they get too hot. IIRC the newer XP Athlons do have some
thermal sensors but rely on external circuity present on the mainboard
to evaluate the readings. So it is not as reliable as the Intel
solution.

But if you read the temperature with some sensor and it says it is OK,
it is probably so. Unless the sensor reading is incorrectly interpreted
in the driver. You can also try to look at the hardware monitoring in
bios. That could give you some idea what temperatures to expect.
The sensor itself should not be dead as the Windows program can read it.

I am using a system where the CPU runs at temperatures around 60C
and the readings from sensors are similar to what bios shows.

Unfortunately I cannot run NetBSD on the system as it cannot access the
hardrive.

HTH

Michal Suchanek