site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com On Jun 20, 2008, at 12:02 PM, darwin-dev-request@lists.apple.com wrote: This information is not available to applications. = Mike _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... 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-). 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? This email sent to site_archiver@lists.apple.com