Long story (background in thread "Newbie: 3 lots of CPU temp in
SpeedFan? 2 of them are overheating ..." from last week) but in short I
have an over heating problem, I've done some tests, and today I
realised that the CPU heat sink is not getting warm at all but by
contrast the much smaller motherboard heat sink does warm up.

So the question I have is, what possible scenarios could stop the CPU
heat transferring to the heat sink? I've pulled it off of the CPU to
check that there is the usual 'grey' solution there and there is. Any
help much appreciated on this one.

I originally thought there was a problem with the heat sink and fan but
to fair the fan is keeping cool a heat sink that is not even getting
warm in the first place, hence my problem with the computer just
switching off. So I need to figure out why the CPU can't transfer its
heat to the heat sink.

FYI I have an AMD Athlon 64 3200 CPU.

Thanks

On 8 Dec 2006 16:55:44 -0800, "Dundonald"
<mark.dundon@gmail.com> wrote:


When the system is idling, the CPU will run cool enough that
the heatsink will not feel hot. You would have to put the
system under good load, perhaps run Prime95's Torture Test
to heat it up and then feel it, or even better to check a
software, hardware monitor report or note the temps reported
in the bios health or hardware monitor page.

If when you took the 'sink off, it looked as though there
was reasonable contact between it and CPU from the
impression left by the thermal interface material, it should
have been good enough to warm the heatsink if the CPU were
overheating. In other words I doubt it was overheating at
all, but you have disconnected this post from the prior
thread so I don't have that information to refer to.

When the system switches off can you immediately turn it
back on with the power switch or is more necessary first,
for example needing to unplug it from AC power for a few
moments?

Dundonald wrote:
When a heatsink that is adequately connected to a heat source is cool,
the the heatsink system is working properly. Heat runs only from hot to
cool. What is this "motherboard heatsink"? You did not gang up a
secondary heat sink to the main heat sink, did you? If you could
accomplish something like this then it is no wonder your CPU is shutting
down.

Secondly, SpeedFan is not infallible.

Q

Dundonald wrote:
Lack of paste. (apparently not your situation).
Heatsink on crooked/backward.
Broken mounts/mounts not seated.


Diagnostic software lying.

I've pulled it off of the CPU to

"Dundonald" <mark.dundon@gmail.com> wrote in message
news:1165625744.386306.326080@16g2000cwy.googlegro ups.com...

You have too much thermal paste. It is NOT a replacement for
metal-to-metal contact. It simply has a faster thermal transfer rate
than *air*. You want only enough to fill the microscopic pits in the
mating materials. It should be translucent when you put it on (i.e.,
thin enough that it looks translucent). Lapping helps to better mate
the surfaces but rare few users bother and even fewer know how to do
it.

Could be cheap paste - if it is paste. Remove it and apply fresh
paste. If it is a pad instead of paste, you just ruined the pad by
removing the heatsink so you will need to remove it and use another
pad (but paste is better provided you know how to apply it).

Could be you did not put the heatsink onto the CPU so that it is flat.
Even if you gob on the paste, it won't help it the heatsink is on at a
angle so that one side of the CPU isn't even touching the heatsink
(and, as mentioned, paste is not a substitute for metal).

Could be you didn't select the correct sensor in Speedfan (i.e.,
whatever is selected for the CPU really isn't the CPU's sensor).
Could be Speedfan won't work with your motherboard; i.e., it doesn't
have the lookup table for that setup or it is using the wrong table, a
defect that also occurs in Motherboard Monitor (MBM). Have you tried
the monitor software from the maker of your motherboard? When you
look at Speedfan and then reboot but go into BIOS, do the temperatures
listed in the BIOS match what Speedfan said?

When specifying temperatures (in your other post), be sure to specify
F (Fahrenheit) or Celsius (C). At 40 F, you are very VERY low in
temp. At 40 C, you are a long way aways from overheating and that is
considered a very good temperature for an AMD (Intels run cooler).
The AMD is rated to 80 C although some setups seem sensitive starting
around 70 C (but also check the BIOS settings to see what is set for
max or shutdown temperature). I have an AMD Athlon XP 2500+ that is
overclocked (by upping the FSB from 166 to 200) because the Barton can
handle that so mine is the equivalent of a 3200+ (same as yours). I
have Speedfan configured to reduce the fan speed until the "Desired"
temperature is 60 C (i.e., when the fans should come up in speed which
increases noise) and warn at 65 C. The BIOS is set to shutdown at 72
C. Stop listening to all those folks that are overclocking and who
are trying to minimize their temperatures. They lower their temps so
they can overclock more (and probably also have to up their voltages,
too). Are you overclocking? I've been overclocking my AMD for
several years and letting it go to 60 C (usually runs at 45-50 C) and
the system has been very stable. I did lap the heatsink and I did use
better paste (but not silver Artic since it is a wasted expense except
to extreme overclockers) along with replacing the standard heatsink
and fan with bigger units. Even if I had not been able to overclock
the Barton, I would still not worry about the CPU running at 50 to 60
C. The AMDs are rated to 80 C (some to 85 C).

If your AMD system is shutting down after only reaching 50 C when you
run your video software, the problem is with your video software, not
with the CPU temperature.

Joel wrote:

Vanguard wrote:

<snip my post>

Thanks very much for all of the posts and help so far.

<snip>

Temp reported in speedfan is similar to the CPU temp reported in the
BIOS.

Temperatures specified are in Celsius.

I've checked every option in the BIOS and there doesn't appear to be a
max or shutdown temperature. Are there hidden menus?

No overclocking here, just the bog standard clock speeds of 10 x 200.

The problem has been recreated by other software that puts load on CPU
such as the Prime95 torture test. I ran that, and once again the
computer switched off during the first test being performed during the
Prime95 torture test. I noticed that the temperature reported in
speedfan was at 53 Celcius when the computer switched off. When I
started the computer up again and went in to BIOS the CPU temp was
reported as 51 degrees Celcius so not far off. Also, as the computer
started to boot up, it kept switching off before windows XP had a
chance to finish loading. This will happen again and again until I
give the computer a chance to cool down. I guess the point here is
that the temp is not always exactly 60 degrees C when the computer
switches off.

I know I can go out and replace the stock fan and heatsink but I don't
want to do that unless I know the exact cause of the problem - I don't
want to shy over it.

Another update:

I did another test also, again starting from cold boot up, where I
disabled the CPUs fan (by removing the power cable from the
motherboard). I wanted to perform this test because as I describe in
the OP when I feel the heat sink it doesn't even feel warm. I booted
the PC up and almost straight away after XP had loaded the computer
switched itself off. So I guess some heat must be transferring from
the CPU to the heatsink, or at least the fan is helping the CPU a
little bit, but I can't understand why even during this test that the
heatsink just didn't feel warm at all.

Dundonald <mark.dundon@gmail.com> wrote:
That last is pretty convincing evidence that the heatsink isnt properly mounted
on the cpu. Some can be put on backwards and dont work properly that way.
Backwards in the sense of 180 degrees off where they should be.

Joel wrote:

THanks JOel.

Rod Speed wrote:

Rod, thanks for the post. I didn't realise that a heat sink could be
put on the wrong way. I'll try spinning the heat sink and fan 180
degrees back around see if that makes any difference. Out of interest,
how can it make a difference, I haven't checked in detail but is the
top of the CPU and the base of the heat sink not flat so in either way
around they should both perform the same?

kony wrote:

I ran Prime95's Torture Test and the machine switched off at 53 degrees
Celcius during the very first test.

I pushed the CPU with the usual test to switch off point and at no time
did the heat sink feel warm.

The computer switches on, goes through BIOS section then as soon as
windows XP starts to load the computer switches off again.

Quaoar wrote:

I just assume it's the motherboard heat sink? I'll take a picture of
the motherboard tomorrow and post to my webspace for you to see. It
may not be motherboard heatsink, but I certainly can't see it connected
to the CPU in anyway and it's much smaller hence my assumption. As I
say I'll post a picture tomorrow.

I know.

paulmd@efn.org wrote:


I never realised the CPU could be placed on backward i.e. 180 degrees
the wrong way. This what you mean? Rod Speed mentioned this too so I
will check tomorrow.

Mounts on what please, the CPU or heat sink?

Possibly but something somewhere is switching the machine off - wish I
knew what and where it was set. I can't see anything in the BIOS.

Dundonald wrote:
The CPU, no. Not without a LOT of force, and you'd have a lot bigger
problem. The heatsink, yes. It can go on backwards. There's a little
lip on socket. Many heatsinks are milled so they can go over the lip.
This means they only go one way, or they make next to no contact with
the chip.

Not all. Of course. This mainly applies to socket 462, and 370, and
older.
The clip from the heatsink to the motherboard.


That's another thing. Every once in a while, there are programming
mistakes in the BIOS. So see if there's a bios update available.
Failing that, after you're SURE the chip really isn't over heating, and
it shuts down anyway, you can disable the CPU shut down feature in the
bios. (Maybe, not all bioses are the same)

CPU shut down temperature or something similarly worded is a key
feature to look for in the bios.

Dundonald wrote:
The asymmetric heatsink problem, was with AthlonXP (the 32 bit processor)
on S462. The contact patch is not in the center of the heatsink, so the
heatsink has to be turned so the contact patch is aligned with the
silicon die. The AthlonXP has a bare die. If the retail heatsink is
turned the wrong way, part of the silicon die ends up with no cooling.

Your Athlon64 is much safer by comparison. It has a heat spreader on the
top of the chip.

Start by reapplying your thermal paste, and see if things improve. Also
check that the heatsink is parallel to the motherboard.

Paul

"Dundonald" <mark.dundon@gmail.com> wrote in message
news:1165691468.152558.175500@80g2000cwy.googlegro ups.com...
No. It's either there or not. You will have to wade through whatever
level of hierarchy they employ in their menues. While they may
monitor the temperature, your mobo may be too old to incorporate
thermal shutdown.

Something else is causing the shutdown. 50 to 60 C is not a threat to
the CPU. Could be a bad sensor, wrong BIOS settings, a defective fan.

Besides temperature, the BIOS is monitoring the CPU fan speed. It saw
zero for fan speed and figured it better shutdown the computer since
overheating was inevitable. A CPU fan not spinning will cause the
computer to shutdown since passive heating is not sufficient for your
CPU. It is possible you have a bad fan that doesn't report its RPM or
fails to do so erratically so the BIOS sees no RPM for the fan and
shuts down.

Dundonald wrote:

<snip>

Hi, as promised here's a few pictures of my motherboard, heat sink's
and CPU etc ... Can someone tell me if the small heat sink is the
mother board heat sink? Thanks.

Pictures are here: http://www.moorcut.co.uk/cpu/cpu.html

Dundonald wrote:

OK GREAT NEWS is that I think I have now fixed the problem. So you
know where I'm coming from it may be best to see the pictures here
http://www.moorcut.co.uk/cpu/cpu.html . Here's what I did. I took the
CPU heat sink and fan off, I took the CPU out its socket and cleaned
off the thermal paste. You'll notice from the pictures that there is
quite a lot of paste on the top of the CPU. I also cleaned a lot of
paste off of the bottom of the CPU heat sink. I also noticed that the
CPU heat sink was flat so I wasn't sure turning it around 180 degrees
would make a difference but I did so anyway. Fired the computer up,
ran the same old test that would usually cause a problem and BINGO -
the highest the CPU temperature got to was 38.5 degrees celcius!!!
Brilliant. As I've previously described it used to just shoot up to 60
degrees and switch off. I then ran the prime95 torture test for a
whole 17 minutes (got bored after that) and the maximum temperature
reached was 49 degrees celcius and the temp was pretty stable. So all
in all it seems good now. Well chuffed! Still not sure whether it was
the removal of the thermal paste (there's hardly any thermal paste on
either the CPU or the CPU heat sink now) or whether it was turning the
heat sink 180 degrees. Any ideas?

The last two questions I have just purely out of interest are:

1. what is the smaller heat sink on my mother board - can someone
confirm that it's a motherboard heat sink or not? It doesn't appear to
be connected to the CPU.

2. Something was switching my computer off at high CPU temperature,
what was it? I have checked every single option in the BIOS and can't
find anything. Anyone any ideas where to find this or what is in fact
doing it?

Thanks for everyone's help so far.

Dundonald <mark.dundon@gmail.com> wrote:
The problem with the possibility of having the cpu heatsink the
wrong way around isnt with the base of the heatsink, its with
how the mounting clips holding it on are done and that isnt
obvious from the pictures.

The smaller heatsink is indeed for one of the chips on the motherboard.

Dundonald <mark.dundon@gmail.com> wrote
The top of what the heatsink mounts to socket wise isnt necessarily
symmetrical, some arent so the bottom of the heatsink doesnt sit
flat on the cpu when its on the wrong way around.

Its not that, just that what the heatsink mounts to on the socket may not be symmetrical.