P5WD2 CPU temp misreads by 10C?

[Justin Scott]

Hi,

I have a P5WD2 (bios 0422) and am trying to get it working properly with
a Pentium D 830. I only have a small Windows 2000 install on it
currently for testing purposes (as eventually I need to pull out parts
from my fully functional, but old, machine).

The problem is the temperatures that the motherboard is reporting seems
entirely out of control. The CPU temp (at room temp, with stock
heatsink+fan) is idling around 65C and goes to 74-75C under load.
Mainboard temp doesn't go much higher than 37C (ambient room temp is
around 25C). However, it does not appear to be throttling. I ran 2
instances of Folding@Home for 3.5 hours last night (and confirmed they
were on both cores), using the ThrottleWatch software, and everything
was perfectly stable. Each cycle in Folding took exactly the same amount
of time (one process had 10 minutes per step, the other was 12, and
those stayed absolutely fine for 3+ hours). That would definitely have
slowed down if the computer throttled.

The only thing not stock in my system is I am using Arctic Silver 5
instead of the stock Intel thermal pad. I had to take my system into a
shop (I had a dead Gigabyte mobo originally that I couldn't troubleshoot
as I didn't have another 955X mobo) and they removed the pad. I don't
think I used too much AS5 when applying it, but that is a possibility as
I haven't used it in years. Intel agreed to send me a new thermal pad. I
know the stock pads aren't as good as AS5 in general, and I hate the
idea of removing the AS5 (if it's possible everything is fine) but it is
something I am considering as I haven't read too many people with temp
issues with Pentium 830's (that isn't easily explainable by ambient
temps or lack of fans).

I am concerned by the time I add my SCSI devices, Atlas 15K drive, etc,
that ambient case temps will be a lot higher and I'm going to have
issues. The case is an Antec 1040AMG (I believe) tower, with 5 case fans
(2 front and 1 side intake, 2 rear exhaust, 1 in the side blowing in).

I am also concerned possibly my setup won't throttle due to Windows 2000
(I can't install XP due to the ancient SCSI card I am using to test
with). But that doesn't explain why the system won't go above 75C and
why Folding never slowed down.

My questions:
1. I read some rumblings the P5WD2 is about 10C too high on its CPU
readings. If this is true, my temps while high, would seem to be ok. Has
anyone else seem "out of control" temps? I would think a 55C idle, 65C
load temp is okay for a dual core. Nothing special, but nothing to hold
up building the system for.

2. Does Windows 2000 properly report throttling? Would ThrottleWatch see
hat?

3. CPU-Z is reporting both cores running at 3ghz. Would throttling cause
CPU-Z to show a slower temp?

Sorry for the newbie-esque questions, it is just getting annoying that
it seems like everything is fine except for me being paranoid about the
temps. I know the dual-core Intels are insanely hot,and everything I
read says they throttle about 74C, but mine is hitting that and showing
no signs of throttling. (and no signs of going higher)

Thanks for any help... (please no "should've gotten an AMD", it wasn't
an option at the time, too bad it's taken so long to get working parts
it ended up I should've waited anyway!)

Justin

 

[Justin Scott]

I just realised I put the wrong idle temps, it actually shows as about
68-69C at idle in Windows 2000 (using the Asus Probe software). Which
makes it even weirder, why does it only go up 5 degrees to full load?

 

[Paul]

I just realised I put the wrong idle temps, it actually shows as about
68-69C at idle in Windows 2000 (using the Asus Probe software). Which
makes it even weirder, why does it only go up 5 degrees to full load?

First of all, section 5.2 on page 79 will give some background
info on your processor.

http://www.intel.com/design/pentiumd/datashts/307506.htm

My first question would be, does "ThrottleWatch" show a status
for each core ? The cores do not have to track one another, in
terms of behavior, so one could be throttled while the other is
not. The load on the cores will seldom be identical. And the fact
that your Folding performance is slightly different should hint at
that.

Page 523 of this Intel architecture doc, also explains the MSR
registers. This is currently at version 16 (25366816.pdf).

http://www.intel.com/design/pentium4/manuals/253668.htm

I guess at this point in time, I would question whether any software
utility is tuned well for dual cores. For example, this link
popped up in a search, as a way to read MSR registers while in
Windows. But in the descriptions, I don't see any evidence this
tool knows about dual cores: http://www.eprotekcomputer.com/

While Googling, I noticed that Everest Home Edition (lavalys.com)
dumps MSR register 19A, 19B, and 19C, so perhaps you could try
Everest and see if it reports throttling. Run it while Folding.
I'd be curious if both cores have MSR registers - I'm presuming
they do, but haven't run into any info yet that says it works that
way.

http://groups.google.ca/group/novel...2x-xp/msg/a33b5ae7fc69e9fa?dmode=source&hl=en

Based on physical behavior alone, I'd say there has got to be
some throttling going on. Your processor is not a mobile, and
only a mobile processor exhibits a tiny temp rise between idle
and 100% loading.

Are you sure the cooler is clamped down properly ? The AS5 may
need a couple of days to "settle in", but in this case, that is
not going to help enough to make your situation a usable one.

The boxed fan should be running flat out at 38C air temperature,
assuming you are not using the motherboard to control the fan.
Make sure Q-fan or anything similar is disabled, in order to get
as close to 12V applied to the fan as possible.

For a new cooler, I'm still waiting to see a review of this one,
the Zalman 9500. Looks to be hanging over the top edge of the
motherboard, so some clearance between the PSU and motherboard
will be required. With some luck, maybe this will blow its
exhaust towards the back of the case.

http://www.anandtech.com/tradeshows/showdoc.aspx?i=2434&p=8

HTH,
Paul

 

[doug]

I've had a p5wd2 with an 840 for about 3 weeks now. My idle temp is
anywhere from about 39c to 48c (mostly near 45c) depending on room
tempture. My computer is in a second floor bedroom on long island and
temps can vary greatly with the weather here, no ac by the way. With
both cores 100% loaded my max temp has been between 69c and 71c. I used
prime95 torture test to load up the cores. Never once did they throttle.
I'm using AS5 just like you. I've used the original pad and AS3 before
this with the same/similar temps.

Also prior to bios 0422 my second core would never go above 2.8 ghz,
even fully loaded. Now both cores are hitting 3.2 ghz under 100%
loading. Asus tech support basically jerked me off telling me it was
everthing but their mb with regard to this issue when I called them
numerious times over this. I even got intel to give me an rma on the 840
over this issue. Two days later 0422 came out and all was fixed.

 

[Justin Scott]

First of all, section 5.2 on page 79 will give some background
info on your processor.

http://www.intel.com/design/pentiumd/datashts/307506.htm

My first question would be, does "ThrottleWatch" show a status
for each core ? The cores do not have to track one another, in
terms of behavior, so one could be throttled while the other is
not. The load on the cores will seldom be identical. And the fact
that your Folding performance is slightly different should hint at
that.

Wow, thanks for the really detailed reply. Some of it is a bit over my
head to completely understand, but I will have to do some reading and
see if it starts making sense (I.e., I am not sure if being able to read
MSR registers will help me since I don't know what I am looking at!). I
will try some of the other programs you mention.

I am not sure if ThrottleWatch reports both cores. It definitely sees 2
processors (independent CPU load graphs). But since I haven't seen any
throttling, I don't know if I will see independent throttling graphs.
CPU-Z has not shown either core dropping below 3.0ghz, though. (and from
what I can tell from reading, it WILL detect that)

Folding has different proteins for each instance; so the fact one takes
10 minutes and the other 12 minutes per step doesn't really indicate a
problem (just that the second core has a tougher protein to work on). I
should try to figure out a way to force them both to do the same work,
or find another tool that I can verify they're both doing the exact same
work.

I am thinking at this point I am going to wait for the Intel thermal
pads to arrive (They're another couple days away, thanks to UPS' "you'll
see it when you see it" service!). If nothing else, it'll give me a
chance to reseat everything and make sure the heatsink is on properly.
Although I can't help but think the heat sink is fine; wouldn't temps
skyrocket and the system shut down? (that is the most baffling part to
me, why even under load the temps only go up 5C and never seem to go
higher).

Fan is definitely running at full speed (around 3600RPM, I think that's
the max, at least from what I've read, I should investigate that more).
I really don't want to deal with aftermarket cooling; I don't plan to
overclock at all (and part of the reason I went with an 830 instead of
840 was to give myself a little thermal headroom) so I am hoping I can
just figure out what is going on.

Doug's reponse is interesting. It does seem like some people aren't
having issues.

Thanks again for your response, I'll report back when I get the chance
to test out a bit more.

Justin

 

[Justin Scott]

I've had a p5wd2 with an 840 for about 3 weeks now. My idle temp is
anywhere from about 39c to 48c (mostly near 45c) depending on room
tempture. My computer is in a second floor bedroom on long island and
temps can vary greatly with the weather here, no ac by the way. With
both cores 100% loaded my max temp has been between 69c and 71c. I used
prime95 torture test to load up the cores. Never once did they throttle.
I'm using AS5 just like you. I've used the original pad and AS3 before
this with the same/similar temps.

Just to clarify, did the AS5 help much at all temp-wise? Or was it
basically the same as the stock pad? Like I posted in my other response,
I am thinking of just putting on a new Intel thermal pad when it arrives
so I can go back to "completely stock" and it gives me a chance to take
it apart, clean it again, and remount everything. If the temps don't
change too much, the Intel pad would at least give me peace of mind that
I am using the right amount. (I have been wondering if I used too much
AS5). Like, say, 5C isn't a big deal at this point, if it suddenly went
from 69C idle to 50C idle I'd be thrilled!

What is strange is I have read a lot of people with 840s with no temp
problems, but I haven't seen too many 830 reports one way or the other.
I wonder if this IS a Bios issue (i.e., the 830s and 840s report temps
slightly differently?). It seems like Asus has been releasing piles of
Bioses for this thing. (nothing like buying brand new, untested
technology!!)

What were you using to see the speeds of the cores? Interesting you had
the 2.8ghz issue. I've read a lot about it... glad this bios doesn't
have that problem!

Thanks for your response!

Justin

 

[doug]

Just to clarify, did the AS5 help much at all temp-wise? Or was it
basically the same as the stock pad? Like I posted in my other response,

A few c perhaps, I'd leave the AS5 on there. Also, when you removed the
old pad off the boxed hs did you clean it real good, with alcohol or
something similar.

I am thinking of just putting on a new Intel thermal pad when it arrives
so I can go back to "completely stock" and it gives me a chance to take
it apart, clean it again, and remount everything. If the temps don't
change too much, the Intel pad would at least give me peace of mind that
I am using the right amount. (I have been wondering if I used too much
AS5). Like, say, 5C isn't a big deal at this point, if it suddenly went
from 69C idle to 50C idle I'd be thrilled!

What is strange is I have read a lot of people with 840s with no temp
problems, but I haven't seen too many 830 reports one way or the other.
I wonder if this IS a Bios issue (i.e., the 830s and 840s report temps
slightly differently?). It seems like Asus has been releasing piles of
Bioses for this thing. (nothing like buying brand new, untested
technology!!)

I thought for sure I had temp problems. Idle was high about 48c when I
built it, and max was 70c. I thought that swing was huge. Ambient temps
have a lot to do with the 'idle' temp. When it was about 60F here last
week I got idle temps in the high 30's. Regardless of the idle temp I go
up to 69-71c under max loads.

What were you using to see the speeds of the cores? Interesting you had
the 2.8ghz issue. I've read a lot about it... glad this bios doesn't
have that problem!

I use CPU-Z to tell me what each core is running at. The mb bios
settings runs the two cores at 2.8 ghz while idling. When they get
called on to do some work they run at their rated 3.2 ghz speed. You can
disable this in bios, but.. then of course you're idle temps will be a
bit higher since it's running now at 3.2 ghz all the time.