
Ask HN: Do I really hear my CPU/GPU or am I getting crazy? - tarikozket
When I drag a really big layer in Photoshop a high pitch sound comes from my Macbook. When I stop dragging the layer, it stops. I have SSD and you can clearly hear that sound when there is no fans running. Is it possible to hear your CPU&#x2F;GPU?
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detaro
You are probably hearing "coil whine", where parts of the power supply
circuits are vibrating and creating noise. If it only happens under very
specific load, you can get the effect of only doing it while doing something
specific. Displays also can make noise depending on what it is displayed,
which probably is a similar mechanism.

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tarikozket
Thank you very much!

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duncan_bayne
Back in the 80s I could "hear" the CPU of my old 8 bit micro by turning the
sound volume up to maximum. I assume that I was hearing some sort of
interference, as that system also used to mess with nearby televisions.

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karlshea
You're not crazy, it's called "coil whine":

[https://www.youtube.com/watch?v=HP73edpQwgc](https://www.youtube.com/watch?v=HP73edpQwgc)

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davelnewton
No.

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tarikozket
OK.

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yunyeng
How do you know fans not running?

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ratfacemcgee
If it's the new Macbook, it doesn't have any fans.

