I'm looking for a way to monitor the CPU's frequency in Windows (7). I've asked this question in other venues, but haven't gotten much of a response.
I've tried using Perfmon, but it has a maximum sampling frequency of 1 Hz. Also, I don't have kernel-level access, so I can't use machine specific registers. There are a number of C functions which can determine the maximum frequency of the processor, but SpeedStep and Turbo Boost make these methods unreliable, as the ones I have tried use an on-chip timer which runs at a constant rate, and thus doesn't reflect the variable processor frequency.
I know that programs such as CPU-Z are able to directly measure the CPU frequency, but I'm at a loss as to how they are actually doing so. Is ACPI a reasonable way of going about this? Any help is greatly appreciated!