Okay, I recently put together a new system (my first time) and everything works great except for one thing: The CPU fan runs at insanely high RPM's for no apparent reason whenever I run a program that requires the cpu to work a little (games, level editing tools, etc). When I'm just using IE or sitting in windows the fan is fine. At first, I was having this problem all of the time, but then I enabled the MoBo fan control so that takes care of it. I already got the heatsink and fan replaced (it was retailed) because I thought I just got a noisy/broken fan. Can ANYONE tell me why I can't get the fan to run normally? My case has five different case fans and at first I thought it was an airflow/airtemp issue, but the craziness still occurs when I run the machine with the side panel completely off. Help!

P.S. - yes, I remembered to use thermal paste between the chip and the heatsync :)

It would help if you posted the EXACT spec of your PC (MOBO/FAN/CPU)

Don't run a CPU fan controll prog unless you know exactly how to work it, you can end up stopping the fan and melting the lot.
If you get a wiered noise ONLY when you put the side panel back on then,,FOOL YOU, you've got some of those power sucking fans on the wrong way round, Causing Air Buffering turbulance.
Remove al those pointless fans and setup 1 fan on the front lower of your case SUCKING air IN, and 1 fan at the top of your case BLOWING air out, If you use a quality fan with a temp monitor and connect to your mobo's system fan socket you will see you Probably didn't need all the other fans..

Fans make noise, that's what they do. Usually, the higher the rpm, the more noise they make. How many fans do you have? maybe 8 or 9? Count them. 5 case fans + 1 CPU fan + 1 PSU fan + 1 Video fan? + 1 chipset fan? = 9. You're gonna have noise! And your CPU fan didn't increase speed "for no apparent reason", games & editing put a lot of stress on a CPU, sitting at idle or surfing the net does not. BTW, I think changing the CPU heatsink-fan voided your Intel retail warranty

I did some tests a while ago because my cpu got hot even with some old dos games that already ran smoothly on my 486DX2. I checked for cpu load and found that even those old games use nearly 100% cpu power while running.

I think that's the reason for your problem:
When the cpu has a high load it gets hot and if it get's hot the fan has to run at a higher speed to keep it cool!

Try the program "speedfan" because it allows to slow the fan a bit but keep a very close eye on your cpu temperature to avoid frying your cpu!

okay everybody. Thanks for suggestions thus far. Here's the exact specs for my machine:

MoBo: Asus P4P-800 dlx
CPU: P4 3 GHz, 800mhz FSB, retailed fan and heatsync
Video Card: ATI Radeon 9800 Pro
(let me know if I'm leaving out something necessary)
RAM: 1GB

Don't worry - I know enough about my CPU temps and fan control not to stop the fan and burn everything up. I do have about six case fans (4 in front, 1 on side, and one in back) plus the CPU fan and video card fan so I'm going to take garuc's suggestion and try unplugging all but the necessary ones and getting a couple of quality ones plugged into the MoBo control.

However, as I said, before I turned on the MoBo fan control, I was having this problem even when the computer was idle with the chip at normal (or even cool) operating temps, so I'm not so sure that the fan is running at 5000 RPM's or more because the chip is hot. Also, when playing games, for example, it runs at high RPM's just sitting at the main menu. I know it should use some resources, but not that many when I'm not doing anything. I know computers and the sounds they make pretty well (since I work around them all day) and I know that my CPU fan (not any of the other ones) is abnormally loud.

And no, I don't think changing out the heatsync/fan voided the Intel warranty because they're the ones that sent it to me.

I forgot one other thing that might help:

If I am running one of the programs that causes the fan to spin at high RPM's, and I Alt+Tab back to windows, the fan calms right back down - even with the other program running in the background. Maybe that adds another piece to the puzzle.

OK, I misunderstood when you said you had the retailed HSF replaced...I thought you meant you replaced it with an "aftermarket" one...

You seem to have a lot of fans...are they balanced? Same number bringing in fresh air as exhausting warm air? Although one of my cases came was a fan reinstalled on the side panel, I don't think this is the best place for a fan. You want good directional airflow from front to back...the side fan just stirs things up & causes turbulence

thanks jam, I'll try and reduce the number and direction of fans blowing inside the case and get more focused airflow.

My question then is this: if I don't have the side panel on the case, shouldn't that give the cpu enough cool air? because it still runs at high RPM's with the case side panel off. Or, does that still not help enough? thanks for all your help!

You don't necessarily have to reduce the number of fans, just try to balance them...CFM in = CFM out.

If your case has an airflow problem, then removing the side panel should prevent the warm air from building up & your CPU will run cooler...if your airflow is balanced & working correctly, removing the panel may actually raise your CPU temp because your fans need a closed system to work effectively

I'm just going to ask this one question because nobody brought it up,Goldenboy dont take it personal.You said you used thermal paste when you put the new hsf in did you rememeber to remove the thermal pad? if it even had one.

good question - there wasn't a thermal pad to remove. No, I'm not taking anything personally here - if I did it would be tough to learn anything new :)

I have the exact same problem, at least I think I do ;).
My CPU-fan is also going crazy, like 5000 rpm, and for no apparent reason. The CPU isn't hot, it runs fine with like 3000 rpm also while working 100%. In fact when the cpu-fan "wants" to run 5000 rpm the temp is getting higher.

I have a ASUS k8V dlx, not the exact same motherboard, but close :)
It could be a problem with the mobo. Cause I don't know what it else could be, the heat isn't at problem, so why does it want to run fast?

Well my <nobr><a class="iAs" style="border-bottom:darkgreen 1px solid;text-decoration:underline;color:darkgreen;background-color:transparent;" href="http://itxt.vibrantmedia.com/al.asp?ipid=7&cc=us&cf=1&ai=10115041&di=64471&ts=20031226141658&redir=http://www61.overture.com/d/sr/?xargs=02u3hs9yoakEVuyyDDRRCmv2rsxvFAs9NVlIAWXUfdEDYFCY3brY3v9ELrjNUxZvO6szyHPhS5bd3zCRoWXucufSmVt455mtFLsL8nI8%2F44SgqWLZcIu6z6sgmcJWM0%2BcixTXc6HnNswxi3t%2B%2Fh5Nj4Hl36Qwusu6%2FtcNTW0J%2BEAgsBoltYwX2D1K9QpAFxEwBlIW5GJxuu8amXua0jThahawKBRTaqQ4PKkZKlC7PTRzDfXl%2F912HGSughYxvAwcN0EZovBIGlFpfT%2FdM%2F5PLRrzpNXMhvGGyA%2FCPheRd" target="_blank" oncontextmenu="return false;" onmouseover="kwE(event,64471);" onmouseout="kwL(event);" onmousemove="kwM(64471);">solution</nobr> was to run the program "speedfan" and set the speed to 3000 rpm. The temp is normal, and it stays there. I wonder if I ever will find out the reason for this fan-madness. This isn't the only forum with no answers.

hey maybe u have a fan controller..like that controls speed of fan..and for some reason u didnt see it so its running at full speed. but i think i remember u said u hit ALT-TAB and it slows down..so maybe im wrong.

here's my latest update:

I discovered that the fan on the side of my case was blowing air out of the case instead of sucking air onto the cpu, so I turned it around. That seemed to help a little, but it didn't take care of my problem completely.

I also installed speedfan. From the readings I get, it does appear to be a cooling problem because when I slow down the fan speeds, the CPU gets warmer. The coolest I can seem to get the cpu (at idle) is about 41 degrees C, but to get that the fans have to run pretty hard. If I play a game, or run some resource intensive programs, the cpu temp gets up above 50 and the fans can't seem to keep it cool. When comparing these temps to friends' systems w/ similar configurations, they seem high. Are they? I know they are within the spec, but still...

Finally, I opened up the case again and noticed that the fans in the front of the case really aren't blowing that much air (compared to the fan at the rear of the case). I think I'm going to buy at least one better fan for the front of the case to see if I can get more airflow (the one's that are there now came with the case and I suspect they are very cheap.

i dont know muck about p4s but that temp seams ok 4 me but my super hot amd rnts at that with oly 2 case fas one near cpu pushin nice coool air over the cpu area one takin hot air away and one blutacked over my hdds untill i save up for hdd coolers and it works fine nice and cooll i have an amd 3000+ and 512mb of 400 ddr so anyway enough bout me my point is r u realy sure all them fans are nessisey think about wher is best for them and plan ou wherer all teh air is going similar to a circut diagram as in blue for cold are where it is going and red for hot ar this way you will get better coling with less fans : ) gud luck oh and make sure ther is slightly more air going in thast comming out not too much just enough too make sure you have a posotive case pressure and dont forget to ake into account the pu fan

sry that shud be dont forget to take into acount the PSC fan it blows air out by the way

again another mistake sry PSU yay i got it correct PSU PSU PSU