Count Processors using C++ under Windows

Question

Using unmanaged C++ on a Windows platform, is there a simple way to detect the number of processor cores my host machine has?

Answer 1

You can use GetLogicalProcessorInformation to get the info you need.

ETA:

As mentioned in the question a commenter linked to, another (easier) way to do it would be via GetSystemInfo:

SYSTEM_INFO sysinfo;
GetSystemInfo( &sysinfo );

numCPU = sysinfo.dwNumberOfProcessors;

Seems like GetLogicalProcessorInformation would give you more detailed info, but if all you need is the number of processors, GetSystemInfo would probably work just fine.

Answer 2

Check out GetLogicalProcessorInformation

Answer 3

I've noticed there's an environment variable NUMBER_OF_PROCESSORS on XP, but I couldn't find it on Microsoft's site. I believe this would be the easiest way, though.