RE: CPU frequency shifting "problems"

Jonathan Morton
2001-09-29T00:40:20Z

> > APM is a lost cause, but the correct solution for ACPI systems is
>to use the
>> PM timer.
>
>This is _completely_ untrue.
>
>The PM timer is (a) inaccurate and (b) slow as hell.
>
>Linux uses TSC because we want high accuracy (nanosecond scale) without
>having slow stuff.

Please, don't confuse accuracy with precision. The TSC is precise
but not accurate. The 100Hz timer is more accurate, especially given
a SpeedStep CPU, but much less precise. It's a subtle distinction,
but an important one.

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