[kevinqian]

Hey guys, I know this isn't HTPC related per se but I do use this laptop as an HTPC and since there are many very technically inclined individuals here, I thought i'd post this issue here in hopes of getting a relevant answer.


I bought a laptop recently with the new Core i5 cpu. There's a noticeable high pitched humming noise coming through the speakers that seems related to cpu usage. I'm not sure if this noise is particular to the cpu, bad shielding in the speakers, or some bad capacitors/inductors on the mobo that creates this singing noise. The noise is prominent when the cpu sits idle, it goes away when something begins to use cpu cycles. Early observations also show sometimes different firefox windows will eliminate it as well.


So any of you engineer types may know what i'm talking about or what's causing this whine? If so, is there any way to alleviate it?


Thanks in advance.

 

[sean.scott]

Just about every Core 2 laptop I have ever used emitted a small high pitched noise that seemed correlated to CPU usage. As a test I am always able to get it to stop temporarily if I click the title bar of a window and move it around my screen. The second I stop moving it the noise would come back.


-Sean

 

[walford]

If the fan(s) for the laptop are speed regulated based on CPU usage it appears that when running at slower speed that the fans are causiing the whining, CPUs don't whine. If this is the case then you need to look at your latptop settings to see if there is a way to have the fans always run at full speed.

 

[kevinqian]

well it's not a mechanical noise coming from a fan. It's definitely a electrical noise coming from an electronic part. Fans would have a whirling sound, this is a very high pitched humming noise. when cpu is idle, the fan doesn't even run and the whine continues.

 

[walford]

So you believe that when the CPU is running at a slower speed that is generatiiing an RF interfernce signal to the laptops speakers driver? Is it also true that you do not have a way in the BIOS to disable any 2 speed CPU options?

 

[jrwalte]

I've heard of sound issues when a CPU is undervolting itself or cutting back on the clock cycle as part of speedstep, etc, to lower power consumption. Since your noise goes away when you make the CPU more active, this could be your issue. Try going to your power settings in Windows and change your power profile to leave the CPU always at 100%. You can try turning off other power saving features, as well. If this works, you can try some lower CPU settings until you reach a point where you no longer have the audio issue.