QueryPerformanceFrequency(  __out LARGE_INTEGER *lpFrequency  );  //返回定時器的頻率

BOOL QueryPerformanceCounter(LARGE_INTEGER *lpPerformanceCount);  //是返回定時器當前計數值

程式碼：

/////////////////////////////////////////////////
#include <iostream>
#include <windows.h>
using namespace    std;
////////////////////////////////////////////////
void main()
{
    _LARGE_INTEGER time_start;    /*開始時間*/
    _LARGE_INTEGER time_over;        
 
/*結束時間*/
    double dqFreq;                /*計時器頻率*/
    LARGE_INTEGER f;            /*計時器頻率*/
    QueryPerformanceFrequency(&f);
    dqFreq=(double)f.QuadPart;
    QueryPerformanceCounter(&time_start);
    Sleep(1000);/*迴圈耗時*/
    QueryPerformanceCounter(&time_over); 
    cout<<((time_over.QuadPart-time_start.QuadPart)/dqFreq)<<endl;//
 
單位為秒，精度為1000 000/（cpu主頻）微秒
}