On 2021/11/03 05:47, Crystal Kolipe wrote: > > Your OptiPlex 9020 is probably a modern i5/i7, which probably contains > > C states similar to this: > > > > acpicpu0 at acpi0: C2(200@148 mwait.1@0x33), C1(1000@1 mwait.1), PSS > > > > Which means when the idle loop calls the "mwait" instruction, the cpu > > will 'instantly' slow down to a lower clock and make other power use > > reductions, until an interrupt happens and requires labour again. > > This high frequcency cycling causes detectable (*) RF noise. In the vast > majority of cases this shouldn't be an issue, but it seems worth noting > just in case we start seeing bug reports of humming on speakers once > this change sees it's way into the next release and more people are > exposed to it.
using mwait is a years-old change
