Cooling advice: O/C C2D in a P180

cjmuk · Post by **cjmuk** » Fri Feb 23, 2007 1:48 am

I've got an E6600 with 4 x 1GB RAM on a P5B Deluxe in a P180. I have replaced the lower and rear Antec TriCools with Nexus fans. The top fan is currently switched off. The CPU is cooled by an Freezer Pro 7. All fans are plugged into the mobo and QFan is enabled to control cooling.

Running overclocked @ 3GHz my typical idle temps are 43C (CPU) and 41C (MB). The CPU temp is fine, but the MB seems a bit high.

Under sustained loads the temps rise a little to maybe 48C/47C respectively. Again.. the mobo is not really in the danger zone, but it seems higher than I would like it to be.

Temps seemed fine until I did two things: overclocked and added the last 2GB RAM. I expect overclocking to heat the CPU more, but didn't expect it to have *much* of an effect on the mobo. I certainly didn't expect the extra RAM to be a problem. I'm waiting to confirm this, but I think if I take the extra 2GB RAM out the MB temp will drop by 3-6C. The sticks feel warm to the touch but the general case temp doesnt seem that warm at all, even running at full tilt.

I know the P5B reports the 'MB' temp rather that the 'case' temp but I kind of assumed that they were effectively the same thing... but are they? There is absolutely no way the case temp is anywhere near 40C is feels fairly cool inside. The CPU HSF is pretty cool to the touch. The mobo heatpipe feels warmer than ambient but not 'warm' by any stretch of the imagination. The RAM stick feel warm, but they are covered by heat spreaders and are theoretically in the main airflow through the case.

Firstly, I wondering whether the MB temps (as reported on the P5B) in the 40s are of concern. Are they even accurate?

Secondly, are these temps healthy? In the short term, I know it's OK, but is it a problem in the longer term? What temps should I be aiming for ideally in this sort of system?

Thirdly, what can I do about them? I tried enabling the top-rear TriCool fan. It certainly helped (even on low settings) to lower the MB temp by a degree or two, but it changed the noise profile (however slightly). I've just blocked off the top fan vent to see if that improves airflow. It should, but the effect on temps is unknown as yet. I was wondering about moving the top fan to the front to act as an intake fan to encourage full front-to-back airflow, but I've no idea if this will work or having any effect.

Any thoughts, observations or suggestions?

pyogenes · Post by **pyogenes** » Fri Feb 23, 2007 5:35 am

the MB temp is a reading off a sensor next to the southbridge chip which is why it looks high.

if you go to Asus' self service tech support site, you'll find that 40 is well below the danger point for that board nad is a perfectly normal temp.

angelkiller · Post by **angelkiller** » Fri Feb 23, 2007 6:11 am

First, adding another 2GB of RAM, is NOT the issue. Yes RAM does produce a little heat, but not enough to make a noticeable difference.

Case temp and Mobo temp are two different things. It is of course hotter as you move closer to the Mobo. The case temp would be taken away from the mobo, and would be lower. The location of the mobo temperature sensor can determine the temperature. For example my Intel board reports three sensors to SpeedFan. a) CPU b) Mobo c) Ambient. The mobo sensor is located either on/in/next to (I forgot exactly) the CPU Socket. This seems like a useless place for a sensor, because this temperture is directly related to the CPU temperature. The "ambient" sensor is between the two channels of RAM. (socket, socket, sensor, socket socket). This temperature is always much cooler than the other two temps and doesn't change much. (This would be the ideal mobo sensor.)

I don't know if any of that helps, but let me try to answer your questions. (Remember that I don't have the board!) The temps are probably of no concern. The heatsink of my 945G chipset is hot to the touch, and the Southbridge, (no heatsink), will burn your finger. (Quite literally). And the sensor is probably pretty accurate. Your temps probably are healthy. As for the long term, I can't say. I would leave them alone. You could try a HR-05 or a NC-U6 This may cool a little bit better than what came with your mobo.

I hope all this helped. If you have any question, or I messed up somewhere, please tell me!

cjmuk · Post by **cjmuk** » Fri Feb 23, 2007 7:29 am

The heatpipe/heatsink arrangement certainly doesn't feel hot to the touch or anywhere near it.

The more I'm reading, the less I trust the MB Temp value; it seems it has merit as an indicator of temp change, but the actual temp is no the issue.

Still, for the good of the mobo, I'm going to experiment with different fan combinations to see if my airflow/cooling is near optimal.

pyogenes · Post by **pyogenes** » Fri Feb 23, 2007 8:29 am

cjmuk wrote:The heatpipe/heatsink arrangement certainly doesn't feel hot to the touch or anywhere near it.

That heatsink/heatpipe arrangement (northbridge and VRM) is thermally decoupled from the MB temp reading. As I already posted, the MB reading is for the southbridge chip which is not connected by heatpipes to anything. Look for the heatsink near the expansion slots.

Also, I'll reiterate that the temps are well within Asus' recommended temp range. But if you're still concerned, adujusting fans and airflow is the wrong approach. Instead:
#1 Remove the foil cover on the heatsink
#2 Replace the TIM on the heatsink with something better like AS5

That'll make a much bigger (if any) difference.

sjoukew · Post by **sjoukew** » Sun Feb 25, 2007 12:33 pm

I have the asus p5w dh deluxe, and the temperatures are also that high. I have checked several points of the motherboard and I couldn't find the spot that was that warm.
According to the asus website FAQ for the p5w dh deluxe

Question

The motherboard temperature reading from P5W DH Deluxe is significantly higher (by almost 10 degrees) than most other motherboards.
Is that normal? If so, what is a safe temperature range on this motheboard?

Answer
It should be normal if the motherboard temperature is within the range of 40~65 degrees Celsius.
The motherboard temperature sensor has been placed between ICH7R Silicon Image 4723.
This is the second hottest place on the motherboard apart from the CPU, also at the airway of chassis fan, to ensure Q'Fan2 is capable of managing chassis fans in the most efficient manner.
Hence, it means the motherboard temperature reading on this board may be quite hot as compared to other motherboards when its overall temperature is not really that much hotter.
Your system should be OK if it is within this temperature range.

I hope this information helps somebody