   Why the "QueryPerformanceFrequency" gives the poor performance in windows7
  I bought a new machine with windows7, CPU is intel Core 2 Quad Processor Q8400,the return value is only 1/10 of that in other machines with windows xp.I google it and it is said that QueryPerformanceFrequency only depends on the CPU,but Quad Processor Q8400 should be better than other old machines (Intel Duo E5300),why does it return the poor value?Can anyone help me?Thanks.   
  It really doesn't matter what the return value of QueryPerformanceFrequency is...You only use that value to 'decode' the values from QueryPerformanceCounter into a "per second" value.   ;  Thanks,I am confused about the return value,since I tested it in several machines with windows xp sp3,the return value is nearly the CPU frequency,but for the new high performance machine, the return value is so small.very strange.Would you tell me how the QueryPerformanceFrequency works?Thanks   ;  It's documented here. There's no need to understand the low low level of the inner workings. That explanation should be more than enough.   ;  Power saving options can effect the output of the function.  Since your other machine is a dual core it may not have been in as low a power state.   ;  Thanks   