System specs - Pentium 4 3.0 Ghz (Intel retail heatsink/fan) Intel D875PBZ ATI9800 Two intake fans Two exhaust fans I just put this confounded system together a week ago, and the processor is idling around 45-50 with mobo temps at 40-45. I realize this isn't too hot, but the annoying thing is the variable speed fan on the processor. It runs at an almost constant 5700RPM which causes an insanely loud whine. I was reading on the forum that hot air from the video card sometimes rises up and overheats the processor (do you think this is an issue?) What can I do to cool/quiet this thing down?

Get a thermaltake spark 7 it has a speed control switch so you can control the speed to whatever you want. also it has a copper base and cools good so you'll be able to run it even lower than your stock one. also when you replace it wipe off the old thermal paste if that's what you got and put some artic silver 3 compound on there. you'll be able to get your temps even lower.

The one about the fan rising up from the video card was a response to a post I did, what I did that that worked was make sure that I had fans the were above the video blowing out air so that the heat would rise up and blow out the back. But it seems like you allready did that so it seems like it should be ok

The new stock HSF has very sensitive temp sensor. You Mobo reported temp is high based on Intel recommendation in keeping system temp below 38C ~ 40C I am using the same HSF in two systems, the fan turns @3100 to 3800 rpm with below 34C system @ 26C room. Make sure the air stream is not blocked by IDE and wiring cables. Depends on case deign, some are better, and some are worst than others. I always like those with lower side panel vent and sufficient front intake without much blocking.

Since it was well over 100°F last week, I added a front fan to wash air over my hdd and a rear fan to exhaust in addition to the side panel and top fans I used. HDD temps went down 6°C and lowered motherboard and cpu about 2°C. Case temps are unchanged at 20-21°C. and noise is minimal. Insure the fans in the front and side fans suck air in and that top or rear fans blow air out. I was under the impression P4's typically run in this temp range with pretty big swings from idle to load.

Thanks for the replies. I remember reading (on Tom's Hardware maybe) that there's been some controversy over whether or not the retail heat sink is sufficient for the P4. So I think I'll probably go with the ThermalTake and some new grease. I think I'll also get a new rear fan (the bottom one only seems to be running at between 1200-1300RPM). It should be around 2500, right? By the way, what's the best way to remove the old thermal stuff from the CPU?

I use 99% rubbing alcohol and q-tips. Also a clean lint free rag if I need to remove a lot of thermal paste from an overdose. I clean the heatsink and processor until they are spotless. Can't hurt to clean the new heatsink too. Tom's Hardware has a bunch of info on this.