Re: P4V8x-MX odd CPU BIOS temperature?

Thanks for the comments, Paul.

I'm starting to suspect it might be correctly reporting temperatures
afterall. Maybe the motherboard or a CPU defect put the CPU in some
kind of slow mode. Is that possible?

I am wondering about this because you inspired me to try a couple of
things.

First, I felt the temperature of the headsink fins after the CPU had
warmed up to stable temperature (something like 27 C). It wasn't even
warm to the touch; it felt pretty much like room temperature to me
(consistent with the reported temperature).

So I then ran tests with the CPU's fan unplugged from the motherboard,
so the only airflow was from the case fans (three 120mm and one 200mm,
all on slowest speed):
- (1) Without any challenging apps, CPU temperatures rose only a
little to the mid-30.
- (2) Then ran the "Hot CPU Tester" app. CPU temp rose *very*
slowly. It took more than 8 minutes for the reported CPU temperature
to reach 60 degrees, at which point I stopped the app and watched
temperatures fall back to 34 C.

From this I conclude that if the sensor were bad, I would've felt heat
on the heatsink during Windows idle, and under load the CPU might even
have halted from the heat. Still, it's hard to believe that the case
fans alone could keep it that cool. . . .

.. . . So this leaves me wondering whether the CPU might be running
extra slow due to something in the BIOS or a defect in the CPU or
motherboard. Relevant BIOS settings all seem to be "auto":

CPU:
- reported CPU: Pentium 4 3.06Ghz
- reported frequency: 3066 MHz
- reported FSB: 533 Mhz
- "Auto" CPU internal thermal control*
- "Auto" hyperthreading
- "Auto" CPU host frequency
- reported actual frequency (Mhz): 133

Chipset:
- "Auto" thermal throttling temperature*
- "Auto" thermal throttling duty cycle*

I also tried disabling the three * 'd thermal control items in the
BIOS: the CPU temperatures were the same as before (both idle and
running Hot CPU Tester).

Very oddly, though, when I run the Benchmark in the Hot CPU Tester
program, my score is only 5450 (even with thermal throttling disabled)
compared with 7400 for comparable P4 HT Northwood CPU's reported at
http://7byte.com/forum/viewtopic.php?t=64&postdays=0&postorder=asc&start=43
(actually they're achieving over 7400-7900, some with a slower 2.8 GHz
Northwood CPU; mine is a 3.06).

(BTW, the sluggishness I was feel seem consistent with running at
5450/7000 of full speed, but that could be my imagination.)

Any suggestions on anything else I should check or tweak, or should I
just be happy it's running so cool?

(It looks like I'll be able to run the system almost silently by going
with a passive heatsink on the CPU and low-airflow slow case fans. If
only I could find a good passive heatsink that would fit this
motherboard.)

Craig in NJ

================================
CraiginNJ wrote:
Well, now my "repaired" P4V8x-MX is showing P4 HT 3.06 CPU
temperatures *less* than motherboard temperature and just 3 to 5
degrees warmer than ambient room temperature. Could this be right or
is it another faulty motherboard?

Asus let me RMA the original rev. 3.00G board. They replaced it with
an older rev 2.01 (whose BIOS I then updated to the latest, of
course). Resulting temperatures (Celsius / Centigrade) per Asus Probe
now:

25 to 33 CPU, depending on ambient temperature & applications run
30 to 39 Motherboard, depending on ambient temperature

E.g., for the last 15 minutes it's been a steady
29 Celsius CPU (86 Farenheit) and
38 Celsius MB (100 Farenheit)
with my ambient room temperature currently about 79 F.

(When CPU was showing about 26 C / 79 F, ambient temperature was
probably 23 / 74 C -- oddly little difference.)

Does CPU < MB make any sense? I do have great case ventilation (two
slow 120mm fans in, one slow 120mm + one slow 200mm out), and the
Zalman CNPS7000-Cu CPU HS/fan is running at unmodulated full RPM since
this MB doesn't control fan speed, but that doesn't seem enough to
explain the low CPU temperatures.

Is it possible for the CPU to be self-throttling down for some crazy
reason? This PC does seem slower than with the original motherboard
(before I bought the P4V8x-MX).

Is it possible that Asus Probe is miscalculating some key adjustment
factor?

Other data:
- This same CPU & HS/fan in my old case and old motherboard had
typical CPU temperatures of around 50.
- "Hot CPU Tester Pro" software was able to raise the CPU
temperature by 5-10 degrees without any noticable change in the MB
temperature, so I'm pretty sure it's reading the right sensor for the
CPU.
- used thin (optimal?) amount of Arctic Silver 5.
- Disabled MBM5 so it wouldn't start with Windows to ensure no
conflict with Asus Probe (Asus Probe was returning N/A for MB
temperature if MBM5 had been run at all, even if just opened and
closed.). FWIW, MBM5 is able to see another sensor that reports
temperatures of 77+ -- I'd guess that's my hard-disk.

Craig in NJ

PS - FWIW, if it's true that my CPU is running this cool, I'd probably
switch to a passive heatsink if I could find one that fits. The
Scythe Ninja I bought won't fit -- I've got plenty of headroom in the
case, but the Ninja is too wide for the motherboard components that
stick up closely around the socket.

.

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