Motherboard/CPU temps

I would like to ask a couple of questions about the temps on my processor and board. I’ve been running this system for going on four years so I it’s not that big of an issue but I do get concerned when I read about all the folks here running a similar setup and reporting CPU temps anywhere from 25 to 36 degrees even while working. Right now, the only app I’m running besides IE7 is MS Word and my CPU temp is 50 while I have a 38 and 36 in system zones one and two. The problem, if you can call it that, gets worse when I put the CPU to work. For the most part, I can keep it out of the high 60s but only when I employ some noisy tactics.

When I first built this rig, my intension was to be able to edit, process, render, and create DVDs out of all my old Sony Handicam 8mm tapes. So I jumped right into it and right off the bat, I saw my CPU temps jump way high. Fortunately, I always run Intel’s Active Monitor so I got a warning and killed my work to cool things down and then I started to investigate the problem.

For starters, I used a “boxed” processor with Intel’s cooling solution already attached to the processor and mounted on the motherboard. (Prescott 3.2E on a D875PBZ). After reading some literature from Intel, I found that it was recommended that this processor should have a special case with a modified or special cooling duct that routed outside air directly onto the processor fan.

I had just built this thing and I used a CoolerMaster case that I liked a lot and it already had a good setup for front intake and rear exhaust fans so I decided to just modify it a bit. I redesigned it just like the ones that Intel described in their article. I simply cut a hole in the left side panel directly adjacent to the processor and then used some light sheet-metal to create a duct that attached to the case panel and extended inward to come within a quarter inch of the processor fan.

Then, because I like to over-do things, I took a 90mm fan that runs on 110 volts and mounted it in the duct opening in the panel. I have a separate switch on that and when I need some extra cooling for some intense CPU operations, I just flip on my “turbo-cooler”. It’s pretty loud but it cools the processor down very quick.

So, the bottom line is, even with this modified case and easy cooling, why are my “normal” CPU temps so much higher than all the temps I see listed for everyone else? Over the years, I thought my fan might have been getting a little louder even though I tried cleaning it with a can of compressed air every once in a while. So I tried various other cooling options including the Zalman CNPS7700-AlCu. That sucker came off the same night it went on. My CPU temps skyrocketed with it. After looking into why such happened, I noticed that the fan on the Zalman drew only a third of the amps that the Intel fan did. Sure, it was quieter but I can’t let the CPU run that hot.

Having had the heatsink on and off so many time, I invested in a tube of Artic Silver and I make sure the processor and mating plate are perfectly clean and smooth and still, all I have to do is fire this thing up and let it idle for a couple minutes and my CPU temp will reach the high forties. The house is normally air conditioned because I live in Florida so my ambient temps around the box shouldn’t be much higher than 27 degrees so I am very puzzled as to why everybody else gets such cool temps and I run in the fifties and sixties.

Sorry for the long post but I felt you needed all the info to help figure out what’s going on. I would appreciate any feedback or ideas but like I said, it’s not burning up and it’s still running so it’s definitely not an emergency.

I know it is hard to believe, but after owning and running this box for going on four years, I just lowered the internal temps nearly five degrees.

This thing had two exhaust fans in the back, (one being the power supply itself), and the second, a much bigger fan located directly below the power supply. and it had one or two or three intake fans, (depending on how you look at it). It has the standard 3 inch intake fan located in the bottom front and blows directly across the hard drives. And then there is the standard fan mounted directly on the processor heat sink. It can be construed as an intake fan because of the duct or plenum I built that funnels outside air from the side of the case directly onto the processor. Then, there is the optinal fan that I installed in the case side that is also in the air stream routed to the processor. I call it the turbo-cooler because while it is still only a 3 inch fan from Radio Shack, it uses 110 volts and I have it on a separate switch and it moves one hell of a lot of air. Necessary when I start rendering digital video.

So, besides this air that gets routed directly onto the processor from the side of the case, all the intake air comes through the front grill-work of this computer. I used a Cooler-Master case and the entire front is this black metal mesh that has a foam rubber like filter material on the inside of it. I just recently had the front cover off becasue I decided to add another intake fan. I had replaced the bigger 6 inch exhaust fan when the computer was new with this supposedly much quieter one. I noticed recently, by using a stick of incense, that my computer operates with a negative air pressure unless I turn on the turbo fan. I noted that all the little ports and plugs had dust sucked into them. So, by using the smoke from a stick of burning incense, I went all around the computer and saw that under normal conditions, my computer was basically starved for air because it was getting sucked into every little crack and crevice there was. So, I decided to put that old 6 inch fan in the front, under the CD-drive where I had a large opening for 3 drive bays I wasn’t using. By removing the case knockouts for the three drive bays, I opened up a large hole in the front of the main case frame that could still remain hidden under the black grill work of the case front cover which has separate optionally removable grill plates for each drive bay. But, with the plate in place, it acted as a fan filter because of it mesh structure and the foam material inside of it.

I read somewhere about how insulating the fan with rubber washers could make it quieter so this time, I mounted the fan with nothing but foam rubber. It’s the kind of foam rubber strips that you use around doors and windows and I packed it in pretty tight all around the fan until I was satisfied the fan couldn’t move or fall out. To my amazement, I can’t even hear that fan even though it is a 6 inch fan right in the front. But, having this all apart, I noted a large buildup of dust packed in the filter-like foam in front of the lower, smaller intake fan in front of the hard drives. So I cleaned that really good and put everything back together. The first thing I saw was a quick drop in all my over-all temps. As much as 5 degrees. I can now idle at under 50 degrees C. which was impossible before. Plus, I now have a positive pressure in the case so my ports and jacks should stay free of dust.

A little time and effort and an old fan made a massive difference today.