Loud fan ONLY when putting side panel on?

could the panel be vibrating? press you thumb into the panel and see if the noise changes.

It's not the panel vibrating. Even when I just hold the panel like in front of the opening (almost like covering it, except not) the CPU fan starts roaring. I read in ONE place that it could be air turbulence or something..but all I changed was the motherboard. The little knob on the CPU heatsink (the one you flip over after putting the heatsink on to clamp it completely shut) is facing the top of the case..where there is a fan. I don't think that is the problem though..

I couldn't find anything else about that air turbulence thing though..

  Could it be a bad heatsink? Should I get a new one like the Hyper 212+?  

Also, could it be bad application of thermal paste?

Or..maybe it is because the knob on the heatsink is facing the fan?


Also..not really related..but is it normal for a Phenom II 970 to spike to 20-30% CPU usage while on an Internet page and while moving the mouse wildly in every direction? I asked my friend with an i7 on his Alienware and he said it only made his CPU usage spike like 1-3%. Mine went from like 2 to 20-30. Then again it is an i7..

I7 has twice the thread count, 4(Phenom)8(I7), so the same work load uses half the cpu percentage on the I7 automatically.

Are you positive of what your temps were before with the old motherboard vs the new one?

Also cpu fan speed is controlled by the motherboard BIOS, and usually there is a smart fan profile to speed the fan up to certain percentages based on cpu heat/voltage. The difference in fan speed is probably a result of difference in fan options in the BIOS. You should be able to play with these settings and get it so your cpu fan only speeds way up when actually needed.

the fan speed thing has got me stumped, i have a fan that speeds up when I remove the filter in front of it, but then i'm removing load on the fan. But there's no way I can think of that moving the cover close to the case would cause the fan to speed up.

@loneninja

Yes the temps are the same.
I checked the BIOS (I have an ASRock 970 Extreme 3), and changed the CPU to manual or whatever, and it didn't help. But how could that be it..? The noise ONLY happens when the cover is on..

@13thmonkey

Could it be I put the heatsink on the wrong way? The knob thing is facing the top of the case, where a fan is.

I really don't know what to do ;(

the knob thing? pictures woudl help

Yeah, I found out that the noise only goes away when removing the side panel FOR A LITTLE while. After that it still makes the noise. The noise is only really bad when playing a CPU-intensive game, or using a CPU-stresser. This proves that it is the CPU.

Could it be that I put the heatsink on the wrong way or something?

Also, by the knob thing, I meant this: http://i44.tinypic.com/2d4apw.jpg
It's facing up, towards the fan, but now that I know it isn't 'air turbulence' because it happens even when the side panel is off, it has to be that I did something wrong with reassembling the heat sink.

Any idea if that's what it is? Should I reassemble it? Should I get a new heatsink like the hyper 212+?

If not, what do you think?  

Have you seated everything correctly? It might be resonance...when you load the CPU up, the fan spins up and it might be the heatsink is slightly loose and resonating off of the mount.

that knob thing is the latch that hold teh hsf in place, it shoud be pressed down to apply pressure to the cpu, and hence let the HSF work. Press it down now.

It is pressed down XP.

I have the same exact issue. I just built a HTPC and it is a tight fit. It has a biostar ta75m+RCH motherboard with the new A8 3870 cpu/fan.

When I'm in Windows, the fan is some what control/managed. But when I reboot the fan screams or if I go into the bios with the cover on, the fan slowly creeps to 5000+ rpm. The temp doesn't change though.

If I take the cover off, the fan is nice and quiet. lol. If I slowly slide the cover over the case, at about 25% covered, the fan speeds up to 5000+ rpm. Its the oddest thing.

I've try turning on and off the smart fan option, fan reacts the same way for both settings.

Then I though it could have been a grounding issue, so I used electrical tape to tape the edges of the case so the cover wasn't touching. Didn't help.

My only thought is that it is an air pressure/flow issue when the cover is on. But If I slide the cover on only 25%, it should still be getting enough air flow.

The other thing i noticed, is that if I take the cover off and place my hand flat above the cpu fan, spaced about the same distance away as the cover, the fan speeds up. lol.

I'm not sure what to do.

pictures? especially a low profile shot showing relationship between the top the hsf and the case lid/side. I've a working theory, based on your last line. which is that the side of the case is limiting the amount of air that the fan can process, this would create a low pressure area just above the fan, allowing a constant voltage to spin it up faster, but it is moving less air, hence the temps climb. you need a bigger gap or a cooler that is rotated 90degrees.

My only concern about this theory, is that my fans spin faster when I remove my air filters, and an air filter is like your hand with lost of holes in it.

I'll have to get you some pictures. It's actually a HTPC that looks like a stereo. Here is the link to the case http://www.newegg.com/Product/Product.aspx?Item=N82E168... . Only the top of the case comes off.

I do like your theory though. I've been thinking about cutting out a spot for a 120mm fan right above the cpu fan in hopes that it would help. When the fan speeds up the temp is not increasing. What is find is odd, when I'm in the bios, the cpu temp is already at 50c. Why? there is no load. When I'm in windows its between 17c - 21c idel. lol Anyways, i'm getting off topic and don't want to highjack this thread as it isn't mine. But I'll try to get some pictures of my setup and hopefully we can figure out both fan issues.

Thx.

note that in bios, the speedstep and other speed management techniques may not come into play, I think that fans that are parallel to the mobo are susceptible to this issue.