p4p800 power fan speed

[edavid3001]

I have an Asus p4p800 running XP and Asus probe.

Asus probe constantly crashes with a divide by zero error. While I
don't understand why Asus can't check for Divide by 0 in Asus probe,
I'd also like to know why this is happening.

The problem is that the power fan reported speed will jump from normal
~2600rpm to over 9000rpm, then report 0, then go back to ~2600rpm.

The thing is, the power fan isn't actually doing this. Nor is the
PSU's sensor falty. I've replaced the PSU with one from a different
manufacture and I get the exact same results.

So the problem must be on the p4p800 motherboard itself, right?

I tried flashing to the latest bios, but that didn't help. I have the
latest ASUS probe I. Asus Probe II don't work on this mobo.

Any ideas? Defective motherboard?

 

[Rob Hemmings]

I have an Asus p4p800 running XP and Asus probe.

Asus probe constantly crashes with a divide by zero error. While I
don't understand why Asus can't check for Divide by 0 in Asus probe,
I'd also like to know why this is happening.

The problem is that the power fan reported speed will jump from normal
~2600rpm to over 9000rpm, then report 0, then go back to ~2600rpm.

The thing is, the power fan isn't actually doing this. Nor is the
PSU's sensor falty. I've replaced the PSU with one from a different
manufacture and I get the exact same results.

So the problem must be on the p4p800 motherboard itself, right?

I tried flashing to the latest bios, but that didn't help. I have the
latest ASUS probe I. Asus Probe II don't work on this mobo.

Any ideas? Defective motherboard?

Asus Probe is the defect IMHO! ISTR that it can't handle fan
speeds of below 600rpm and gives erroneous results.
BTW, you can't have more than one system monitor installed,
so make sure you don't have Motherboard Monitor (MBM5)
or SpeedFan etc installed as well, as they'll interfere with each
other. Personally, I dumped Probe and use MBM5 which can
also monitor HD temps.
HTH

 

[edavid3001]

Yea, I tried MBM5 but I need to get to the DMI info and MBM doesn't
appear to do that. MBM5 is removed from this system. I am aware that
both hook into the same place and you can't run two at the same time,
just like you can't run two antivirus programs. I found that out the
hardway months ago.

I run ASUS probe on many other PC's without this error, so something
else seems to be wrong. The fans runs at a constant speed on this
machine, not variable like the ones I have in my home PC.

Since the sensor is in the PSU, and the PSU only hooks up via the 20PIN
and the 4PIN, the speed must be sent over one of these PINS to the
Motherboard. Since replacing the PSU didn't make a difference, I think
the problem is in the Motherboard reading the voltage on the pin
somehow.

I guess I could watch it in BIOS and see what happens to verify?

 

[Rob Hemmings]

Yea, I tried MBM5 but I need to get to the DMI info and MBM doesn't
appear to do that. MBM5 is removed from this system. I am aware that
both hook into the same place and you can't run two at the same time,
just like you can't run two antivirus programs. I found that out the
hardway months ago.

I run ASUS probe on many other PC's without this error, so something
else seems to be wrong. The fans runs at a constant speed on this
machine, not variable like the ones I have in my home PC.

Since the sensor is in the PSU, and the PSU only hooks up via the 20PIN
and the 4PIN, the speed must be sent over one of these PINS to the
Motherboard. Since replacing the PSU didn't make a difference, I think
the problem is in the Motherboard reading the voltage on the pin
somehow.

I guess I could watch it in BIOS and see what happens to verify?

You could well be right. I must admit I've never seen Probe die
with a divide by zero error. Perhaps there's some part of MBM5
still in the registry? Let's hope it isn't a motherboard fault, but it
is beginning to sound possible/likely..
HTH

 

[Michael W. Ryder]

I have an Asus p4p800 running XP and Asus probe.

Asus probe constantly crashes with a divide by zero error. While I
don't understand why Asus can't check for Divide by 0 in Asus probe,
I'd also like to know why this is happening.

The problem is that the power fan reported speed will jump from normal
~2600rpm to over 9000rpm, then report 0, then go back to ~2600rpm.

The thing is, the power fan isn't actually doing this. Nor is the
PSU's sensor falty. I've replaced the PSU with one from a different
manufacture and I get the exact same results.

So the problem must be on the p4p800 motherboard itself, right?

I tried flashing to the latest bios, but that didn't help. I have the
latest ASUS probe I. Asus Probe II don't work on this mobo.

Any ideas? Defective motherboard?

The sensor will only read the speed of fans connected to the power
supply fan header on the motherboard. If you don't have anything
connected to the header, or if the fan you connected to the header does
not report speed, you need to disable the reading in the Bios.
Otherwise it is waiting for a signal that does not exist and providing
spurious results.
The monitoring programs can not read the speed of a fan that is not
connected to the sensors on the motherboard.

 

[GHalleck]

Yea, I tried MBM5 but I need to get to the DMI info and MBM doesn't
appear to do that. MBM5 is removed from this system. I am aware that
both hook into the same place and you can't run two at the same time,
just like you can't run two antivirus programs. I found that out the
hardway months ago.

I run ASUS probe on many other PC's without this error, so something
else seems to be wrong. The fans runs at a constant speed on this
machine, not variable like the ones I have in my home PC.

Since the sensor is in the PSU, and the PSU only hooks up via the 20PIN
and the 4PIN, the speed must be sent over one of these PINS to the
Motherboard. Since replacing the PSU didn't make a difference, I think
the problem is in the Motherboard reading the voltage on the pin
somehow.

I guess I could watch it in BIOS and see what happens to verify?

A divide by zero error is a version of the runtime error and
is typically related to software and memory utilization and
can also be related to over-clocking or mis-clocking. Just
how good is the installed RAM? And there is no apparent over-
clocking? An alternate solution would be to install another
version of AsusProbe, either older or newer. And FYI, the PSU
fan tach cable is a single-wire lead.

 

[edavid3001]

The PSU does report fan speed. I have replaced the PSU with another
that DOES report fan speed and it does the same thing. It's a
different PSU vendor, so the problem is not with the PSU. The PC is
on an APC 1200Kva which gives out good power.

The PC is not overclocked. I went ahead and swapped out the RAM as
suggested. I've replaced four 256MB sticks with two 1GB sticks. The
problem persists.

The divide by zero error comes from ASUS probe trying to chart the
power fan graph. This is because there are times when the reported fan
speed is zero. If I disable charting, Asus probe does not die. I
have tried every version of Asus probe released in the last year and
each do this. Asus probe should monitor for divide by zero, imho.

I watched the BIOS for about 5 minutes and didn't see this occur in the
BIOS, but I really need to spend more time watching the BIOS. Asus
probe can go over 5 minutes without having this fluctuation.

Where would I look for MBM in the registry? I don't see anything for
MBM5 in there. A search for MBM isn't finding anything that looks like
MBM.