CPU overheating

[Dennis]

The other day, part way through processing an avi, my computer suddenly shutdown. A quick check of the UPS showed that power was okay and I could still hear the TV in the lounge room. Hmmm. Ah well, re-boot and see what happens. As I re-booted, I hit the Del button to get into the BIOS for a physical system check and just happened to notice the CPU temperature climb to 90 deg C and klunk, down she went again.

I opened the case (after removing power) removed the OEM CPU fan and discovered that the heat transfer compound had somehow migrated off the main thermal contact area so I popped down to the local Computer Shop and purchased a tube of Artic Silver thermal compound. After re-doing the thermal contact pad, I re-assembled the system. Fingers crossed and when I powered on, the CPU temp in the BIOS settings started off around 52 Deg C and climbed to around 70 deg C before stabilizing.

Still not happy with the temperatures, I decided to replace the P4 3.4G HT fan and the Radeon 9800XT graphics card fan with a Zalman CNPS7700-Cu Low Noise CPU Heatsink/Fan and a Zalman VF700-CU High Performance Video Card Cooler respectively.

Now, the CPU idles at around 38 Deg C and when I run my weekly Norton’s anti-virus scan, it climbs to around 57 Deg C. I had to cut off 4 of the copper cooling vanes from the Zalman VF700-CU High Performance Video Card Cooler, as they fouled a couple of capacitors on the board, despite being compatible with the card!.

All in all, a good job for $100 and a couple of hours work. Our study is on the Western side of our house and is often at 30 Deg C in the summer months, even with the windows open and the ceiling fan running.

Cheers

Dennis

[cjmarsh81]

Good idea to change the CPU heatsink/fan. Do you also have at least one case fan to circulate air?

Unless you are playing 3D games I do not think it was necessary to change the video card heatsink/fan. Video editing gets processed by the CPU and not the video card. The video card only displays the image.

[stinky]

If in doubt there are quite a few utilities free for download that will monitor cpu temp - trigerring alarms and shutting down the pc at a given temp.

[Dennis]

Hi Guys

Thanks for the feedback and tips –much appreciated. As part of just growing confident with tinkering with my PC, I decided to replace the graphics fan as I had the case open for changing the CPU fan, and just wanted to dabble!

The case is a Thermaltake Armor and has the following fans:

Front: 102mm (intake?)
Rear: 120mm (blow?)
Rear: 80mm in PSU
Rear: 80mm for (unused) 3 drive caddy
Top: 80mm

I downloaded the Gigabyte “EasyTune5” utility for my motherboard after the system shut down automatically last time. This “appears” to display the same information as the BIOS, but through the Windows GUI once the PC has booted.

One thing that really puzzles me, is that the BIOS always reports the CPU temp as being at least 10 Deg C greater than the ET5 Windows utility? Surely they cannot be using different sensors?

Cheers

Dennis

[cjmarsh81]

My laptop shows a higher temperature in the bios than in Windows as well. I don't think it is a problem reading the sensor.

What I think it is, is in DOS or the BIOS the CPU is running flat chat. Once Windows is booted, windows tells it to slow down while it is not being used. I know this is the case with my laptop because it is a centrino and the speed goes up and down when needed.

Maybe the same thing is happening in your desktop?

[stinky]

A lot of the utilities that dispaly temp in the GUI have a calibration possibility.

[Dennis]

Thanks again guys, for enlightening this wannabe nerd!

Cheers

Dennis

[Dennis]

Just noticed the following differences (whilst browsing IIS) after fitting the new beaut 916gm Zalman CPU fan/cooler:

System fan:
Pre-Zalman = 6200rpm.
Post-Zalman = 2700rpm

CPU fan:
Pre-Zalman = 3000rpm.
Post-Zalman = 800rpm.

CPU Temperature:
Pre-Zalman = 72 Deg C.
Post-Zalman = 47 Deg C.

I am hoping that this will magically translate into improved avi's of Saturn and Jupiter, once the clouds have cleared!

Cheers

Dennis

[cjmarsh81]

I don't know about improved avi's, but at least you should be able to finish one without the computer turning off.