如何取得CPU的速度

作者:隨心工作室 資料來源:http://www.aslike.net/ 在Win9X系統中利用如下函數可取得CPU速度，精確度很高：

//---------------------------------------------------------------------------    int __fastcall Frequence_MHz()
{
        LARGE_INTEGER ulFreq, ulTicks, ulValue, ulResult;
    __int64 ulEAX_EDX, ulStartCounter;            // it is number of ticks per seconds
        QueryPerformanceFrequency(&ulFreq);            // current valueofthe performance counter
        QueryPerformanceCounter(&ulTicks);            // calculate one second interval
        ulValue.QuadPart = ulTicks.QuadPart   ulFreq.QuadPart;            // read time stamp counter
        // this asm instruction load the highorder 32 bit of the
           register into EDX
        // and the lower order 32 bits into EAX
        _asm {
                rdtsc
                mov DWORD PTR ulEAX_EDX, EAX
                mov DWORD PTR (ulEAX_EDX   4), EDX
        }            // start no of ticks
        ulStartCounter = ulEAX_EDX;            // loop for 1 second
        do {
                QueryPerformanceCounter(&ulTicks);
        } while (ulTicks.QuadPart <= ulValue.QuadPart);            // get the actual no of ticks
        _asm {
                rdtsc
                mov DWORD PTR ulEAX_EDX, EAX
                mov DWORD PTR (ulEAX_EDX   4), EDX
        }            // calculate result
        ulResult.QuadPart = ulEAX_EDX - ulStartCounter;            return (int)ulResult.QuadPart / 1000000;
}
//---------------------------------------------------------------------------

在Win2000/XP系統中，直接可以從注冊表中取出，其鍵值為： [HKEY_LOCAL_MACHINE\Hardware\Description\System\CentralProcessor\0] "~MHz"= 網路志工聯盟----Visita網站http://www.vista.org.tw ---[ 發問前請先找找舊文章 ]---