High-Resolution Timer Using Mach Time

mach_timer.mm

#include "mach/mach_time.h" //NOT #import

mach_timebase_info_data_t mach_info;
mach_timebase_info(&mach_info);

uint64_t start = mach_absolute_time();

//do stuff to time

uint64_t finish = mach_absolute_time() - start;

finish *= mach_info.numer;

NSLog(@"Time in ms: %f", finish / (mach_info.denom*1000000.0f));