Re: cpu frequencies
Re: cpu frequencies
- Subject: Re: cpu frequencies
- From: Michael Smith <email@hidden>
- Date: Fri, 20 Jun 2008 20:09:10 -0700
On Jun 20, 2008, at 12:02 PM, email@hidden wrote:
I would like to retrieve the current cpu frequency of each cpu/core
installed (this frequency can change depending on the use -thanks to
the
intel speedstep technology-).
This information is not available to applications.
Currently I'm using the asm instruction "rdtsc" (which retrieve the
number
of tick elapsed since the cpu started) then using a timer to
calculate the
frequency.
This is working fine, but this is not reliable for multi-cpu/core
architecture.
It is not reliable in any fashion, even on a single-core system. On
some systems the TSC will stop when a core or package enters the
deeper C states, for example.
On many mobile systems, the core clock frequency changes very
frequently and can spend a proportionately large amount of time well
below the device's maximum.
What are you trying to do, and why do you think that knowing the
"current" core clock frequency will help you?
= Mike
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