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QPC offers high resolution (often <1 microsecond). It’s based on a hardware counter (HPET, TSC, or ACPI PM timer). The problem? It is . QPC gives you ticks since system boot, not an absolute date and time.
Modern software development toolsets (like Visual Studio v145) and languages (like Rust 1.78+ ) have raised their minimum requirements to Windows 10 or 8.1. These newer versions use GetSystemTimePreciseAsFileTime because it provides sub-microsecond precision by leveraging the highest resolution hardware clock available. Windows 7, however, only supports older, less precise timing methods. Solutions and Fallbacks
In 2011, Microsoft released a hotfix (KB2553549) titled "High-resolution absolute system time measurement function is made available for Windows 7" . This update backported GetSystemTimePreciseAsFileTime to and Windows Server 2008 R2 SP1 . getsystemtimepreciseasfiletime windows 7
: Some third-party libraries may offer similar functionality by leveraging other high-precision timing mechanisms available on Windows 7.
wmic datafile where name="C:\\Windows\\System32\\kernel32.dll" get Version QPC offers high resolution (often <1 microsecond)
If you’ve ever needed to measure short time intervals (like benchmarking code, network latency, or frame timing) on Windows, you know the journey: GetTickCount , QueryPerformanceCounter , GetSystemTimeAsFileTime ... and then there's GetSystemTimePreciseAsFileTime .
While Windows 7 does not natively support GetSystemTimePreciseAsFileTime , there are scenarios where an application might still benefit from its precision: static HMODULE hKernel32 = NULL
To empirically test the function on your Windows 7 machine:
If you call it blindly on a stock Windows 7 machine, your application will crash with "Entry Point Not Found."
void GetHighResUtcTime(FILETIME *ft) static GetSystemTimePreciseAsFileTimePtr pFunc = NULL; static HMODULE hKernel32 = NULL;
For subsequent requests, calculate the elapsed time using QueryPerformanceCounter and add it to your base time. 4. Summary Table GetSystemTimeAsFileTime GetSystemTimePreciseAsFileTime Windows 2000 Precision < 1 microsecond Windows 7 Support Yes No
