QueryPerformanceFrequency(&liFrequency); QueryPerformanceCounter(&liCurrentCount);
Enter GetSystemTimePreciseAsFileTime . Officially introduced in and Windows Server 2012 , this API delivers sub-microsecond precision (typically in the tens of nanoseconds) by reading the system’s performance counter. getsystemtimepreciseasfiletime windows 7 patched
timeBeginPeriod(1); GetSystemTimeAsFileTime(...); // Now ~1 ms resolution timeEndPeriod(1); Downside: Increases power consumption and CPU load. Get the absolute time by reading performance counter and applying the system time offset calculated from last adjustment. 3. GetTickCount64 + GetSystemTimeAsFileTime Low resolution but thread-safe and stable. 4. Upgrade to Windows Embedded 8/10 If possible, move to a modern Windows version that natively supports the precise API. Community Response and Official Microsoft Stance Microsoft has never officially supported GetSystemTimePreciseAsFileTime on Windows 7. In MSDN documentation, the "Requirements" section clearly states: Minimum supported client: Windows 8 . Get the absolute time by reading performance counter
In various GitHub issues and developer forums, Microsoft engineers have reiterated that they will not back-port the API. The community patch thus remains an unsupported, "use at your own risk" solution. llElapsed /= liFrequency.QuadPart
// Calculate elapsed time in 100-ns units LONGLONG llElapsed = (liCurrentCount.QuadPart - llBasePerformanceCount) * 10000000; llElapsed /= liFrequency.QuadPart;