CPU makes high-pitched noise

[anonymous_c]

I have a VIA C3 533MHz fanless CPU. I'm using it as a server. However,
when the CPU starts to do something, it emits a high-pitched noise.
It's not loud, but noticeable. I can handle it -- it's no louder than
my PC fans. But I'm curious as to why it's happening, and if I can stop
it.

I've ruled out everything else but the CPU/mobo. I've unplugged the
harddrive, but it's still making the noise. The CPU (obviously) has no
fans, and neither does the PC. It's not the PSU, as I've used it before
on a much beefier system (this one uses about 15W total) with no
problems.

If the CPU is idling, however, there is no noise.

Anyone have a clue?

 

[Robert Redelmeier]

I have a VIA C3 533MHz fanless CPU. I'm using it as a
server. However, when the CPU starts to do something, it
emits a high-pitched noise. It's not loud, but noticeable. I
can handle it -- it's no louder than my PC fans. But I'm
curious as to why it's happening, and if I can stop it.

I've ruled out everything else but the CPU/mobo. I've
unplugged the harddrive, but it's still making the noise. The
CPU (obviously) has no fans, and neither does the PC. It's
not the PSU, as I've used it before on a much beefier system
(this one uses about 15W total) with no problems.

Most likely the mobo powersupply regulators/inductors.
They can switch at high-audible ranges.

If the CPU is idling, however, there is no noise.

Powersavings.

-- Robert

 

[krw]

Most likely the mobo powersupply regulators/inductors.
They can switch at high-audible ranges.

Capacitors can sing too. Many types are microphonic (both
directions).

Powersavings.

"Sounds" likely.