linux get Cpu Count?

You can read /proc/cpuinfo. This will have one entry for each core. If the processor has Hyper Threading you will see two for each core. Although I think the file has values that could be used to determine actual physical processors.

OpenMP also has the omp_get_num_procs function, if OpenMP were an option.

boost also has boost::thread::get_hardware_concurrency() or boost::thread::hardware_concurrency() or something like that

sysconf(_SC_NPROCESSORS_ONLN)

gumpy Thanks , i just found the same solution on another forum.