| Operating System | Native Support | Notes | |----------------|----------------|-------| | Windows 10 / 11 | Yes | Full native support | | Windows 8 / 8.1 | Yes | Introduced with Windows 8 | | Windows 7 | No (without update) | Not present in original RTM or SP1 | | Windows Vista / XP | No | No update available |
– Measuring frame render times precisely to detect micro-stutters. getsystemtimepreciseasfiletime windows 7 upd
This article dives deep into the availability, update requirements, and practical implementation of GetSystemTimePreciseAsFileTime on Windows 7. GetSystemTimePreciseAsFileTime is a kernel32.dll function that retrieves the current system date and time with the highest possible resolution (<1 microsecond). Unlike its predecessor, it is not affected by the system's timer interval (the "clock tick"), making it ideal for sub-millisecond timing. | Operating System | Native Support | Notes
Introduction In the world of Windows system programming, precise time measurement is critical for performance profiling, network synchronization, database logging, and multimedia applications. For years, developers relied on GetSystemTimeAsFileTime to obtain the current system time. However, this function had a significant limitation: its resolution was typically constrained to anywhere from 10 to 16 milliseconds, depending on the system timer resolution. Unlike its predecessor, it is not affected by
– Align timestamps across multiple machines with clock synchronization like NTP.
typedef void (WINAPI *GetPreciseTimePtr)(LPFILETIME); GetPreciseTimePtr preciseTimeFunc = nullptr; void InitPreciseTime() HMODULE hMod = GetModuleHandleW(L"kernel32.dll"); if (hMod) preciseTimeFunc = (GetPreciseTimePtr)GetProcAddress(hMod, "GetSystemTimePreciseAsFileTime");
Without KB2813345, these applications on Windows 7 suffer from 10-15ms granularity, causing incorrect ordering and statistical bias. If you are shipping an application that targets Windows 7 and needs high-precision time: Option A: Static Dependency Declare the function in your code and link normally. The application will fail to start on unpatched Windows 7 systems. Use this only if you can require customers to install KB2813345. Option B: Dynamic Load (Recommended) Load the function at runtime with GetProcAddress . Fall back to GetSystemTimeAsFileTime + QueryPerformanceCounter hybrid if not available. This ensures compatibility across all Windows 7 SP1 systems (patched or not).