get number of CPUs in C++ MFC application

Question

Hi!

I write a little raytracer and i'd like to query how many cpu cores (or virtual cpu cores if the cpu uses hyperthreading) the current computer offers, such that i can instanciate as many threads to get better parallel rendering.

How can I do that using C++?

thanks!

Answer 1

You can get the number of physical processors by calling GetSystemInfo and checking the dwNumberOfProcessors field of the SYSTEM_INFO structure. You can get the number of logical processors by calling GetLogicalProcessorInformation.

Answer 2

Try the GetSystemInfo function. It returns a SYSTEM_INFO struct which has a dwNumberOfProcessors member.

Answer 3

The Win32 API function GetSystemInfo will return a SYSTEM_INFO structure with the information you need. Specifically, check the dwNumberOfProcessors member variable.