High pitch noise

[spyke562]

Hello Everyone,

I an recently built a new PC. After completing it I am noticing a really high pitch humming noise. Sound like a dog whistle or like the noise a TV makes when it is turned on. I cant really sit next to my PC because of it. From doing a butt load of troubleshooting I finally put my ear right behind the CPU on the back side of my case and it is definitively coming from the CPU (or very near that location). There are a bunch of capacitors around it.

I have ran CoreTemp and Prime95 for about 5 hours and the temps stayed around 45C. I seems like when there is HD activity the noise stops for a sec then starts back up. When Prime95 was running I really didn't hear it.

My question is do you think its the CPU or the Motherboard? I bought both from Newegg and wanted to RMA them but not sure which one.

I have read that it could be the PSU as well but the noise is sure coming from the CPU (or very near it).

Motherboard - GIGABYTE GA-Z68X-UD3H-B3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard

CPU - Intel Core i5-2500K Sandy Bridge 3.3GHz (3.7GHz Turbo Boost) LGA 1155 95W Quad-Core Desktop Processor BX80623I52500K

PSU - CORSAIR Professional Series HX750

Thanks for the advice...

 

[Proximon]

A noise like that can fool you. Try using a cardboard tube or stethoscope to isolate the noise better.

It's very odd that you would have a 45C load temp though. What cooler is on there? Stock? I would expect at least 50C... perhaps your ambient temps are very cool?

See if the noise changes if you remove your GPU and run just onboard video? That would point to the PSU as well. The noise is changing with HDD activity.... but why not with CPU activity?

Is your CPU actually running 4 threads in Prime95? Is the voltage and multiplier changing correctly at loads? CPU-Z will help with that if you don't have it yet.

 

[geofelt]

Try stopping the cpu cooler fan to see if the noise stops. Sometimes the fan cable rubs against the fan.

 

[spyke562]

Hi Proximon...thanks for the reply.

I used a cardboard tube from the toilet paper roll (nice idea by the way) and isolated the noise to right behind the CPU on from the back of the motherboard. I am not sure if its the CPU or something on the motherboard around the socket making the noise.

As for my temps I think my ambient is just low. Plus I am using a Hyper 212 Plus as my cooler.

I have removed each device one at a time and then with just the PSU powering the motherboard and an OS drive and still hear the noise. However when I run Prime 95 I don't hear the noise. I also downloaded and ran PerformanceTest from PassMark on my OS disk (only one in right now) and didn't hear the noise either. It's almost like it does it when it's idling?

I have confirmed, Prime 95 is running 4 threads. When Prime 95 is not running I hear the noise and my voltage multiplier is at x16.0. While still hearing the noise I started Prime 95 and it stopped right away. My voltage multiplier went to x34.0.

I am not overclocking, this CPU (i5 2500k) is at stock settings. I have also reseated the CPU and cooler.

To Geofelt, thanks for the hint, I just stopped the fan with my finger and I still hear the noise. I also stopped my front and rear fans, still hear it

WHAT THE HECK MAN!!!

Thanks for any other input you might have...

 

[geofelt]

Sometimes electronics can have a resonance sound. Google "coil whine".
You might try touching some of the components with your finger to see if the sound stops.

If the sound is definitely coming from your motherboard, you should probably rma it while you can.

 

[Proximon]

Yep. It's a strange place to develop a whine, but at least I heard of something new

 

[geofelt]

Can you take everything out of the case?

It might help isolate the problem.

 

[spyke562]

Hey guys,

Thanks for the additional tips. I actually did try touching the components and have not found one that stop the noise. I will keep reading about coil whine, it appears a lot of other have the same issue with other builds.

I just started the RMA process for both my CPU and motherboard on newegg. Tomorrow I will swap the CPU out with one I have at work. If it stops I know its the CPU, if not its got to be the motherboard. I was thinking about just sending them both back to newegg but I don't know how that would fly?

I have taken everything out of the case. I just had a HD with and OS, PSU, memory, CPU and motherboard. I am positive its coming from the motherboard or CPU socket area. Just not sure which component it is.

Thanks for all the posts...I will post back tomorrow with an update. Just in case anyone want to know

 

[spyke562]

***update***

I think I may have found the reason. So after searching for "Coil Whine" (thanks geofelt) I came across the C3/C6 State Support. I went in my BIOS and set the setting to disabled (was set to Auto). Rebooted and ran for a bit and did not hear the noise. Then I went back into the BIOS and set it back to Auto, rebooted and I hear the noise again.

I was thinking about simply leaving it off. However will this have any negative impact? In the future I would like to OC my CPU, will this setting come back to bite me?

Before I disabled the C3/C6 settings I disabled the EIST Function, but that did not make a difference.

C3/C6 State Support (Note 1) Allows you to determine whether to let the CPU enter C3/C6 mode in system halt state. When enabled, the CPU core frequency and voltage will be reduced during system halt state to decrease power consump-tion. The C3/C6 state is a more enhanced power-saving state than C1. Auto lets the BIOS automatically confgurefthisfsetting.f(Default:fAuto)

CPU EIST Function (Note 1) Enables or disables Enhanced Intel SpeedStep Technology (EIST). Depending on CPU loading, Intel EIST technology can dynamically and effectively lower the CPU voltage and core frequency to decrease average power consumption and heat production. AutofletsfthefBIOSfautomaticallyfconfgurefthisfsetting.f(Default:fAuto

 

[geofelt]

Good job!!!

I think EIST is useful, and since it is not part of the problem, leave it on.

I have eist enabled, and when not under load, the clock reduces to 1600, even with a oc to 4.0.
Under load, it goes to 4.0 which is all I need.

I am not knowledgeble on c3/c6, but it appears to me that it is an effort to reduce your energy consumption eve more when halted. I doubt that it matters much.

Personaly, I do not usually shut down, but sleep to S3 state which leaves everything in ram for quick reactivation. When I sleep, there will be nothing that needs saving in ram.

 

[spyke562]

Best answer selected by spyke562.