Replace QPC to RDTSC Timer in games

[Kaldaien]

I'm not convinced this is a good idea

The reason we moved away from using RDTSC for timing is because 1) CPUs have dynamic frequency scaling and 2) each CPU core has a different RDTSC timestamp.

QPC is monotonic and the frequency is constant no matter what CPU core any timing code happens to be running on.

[pox02]

i would like to update code so u guys get more game feeling by using the function QueryThreadCycleTime enjoy

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    QueryThreadCycleTime(GetCurrentThread(), &st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    QueryThreadCycleTime(GetCurrentThread(), &ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

[Bobo]

what exactly is this and how do you use it ?

[Aspector]

i would like to update code so u guys get more game feeling by using the function QueryThreadCycleTime enjoy

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    QueryThreadCycleTime(GetCurrentThread(), &st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    QueryThreadCycleTime(GetCurrentThread(), &ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

And how do we use it or compile it?

[AndreyRGW]

i would like to update code so u guys get more game feeling by using the function QueryThreadCycleTime enjoy

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    QueryThreadCycleTime(GetCurrentThread(), &st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    QueryThreadCycleTime(GetCurrentThread(), &ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

I compiled RDTSC with your code, but I didn't notice any changes compared to the original.

[pox02]

i would like to update code so u guys get more game feeling by using the function QueryThreadCycleTime enjoy

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    QueryThreadCycleTime(GetCurrentThread(), &st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    QueryThreadCycleTime(GetCurrentThread(), &ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

I compiled RDTSC with your code, but I didn't notice any changes compared to the original.

Try add SetProcessAffinityMask in first core see if any improvement

Code: Select all

SetProcessAffinityMask(GetCurrentProcess(), 1);

test fix overhead of QueryPerformanceCounter didnt try for long time so give any updates of it

Code: Select all

 LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    1000000 * (ed.QuadPart - st.QuadPart), fq;
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
    

[AndreyRGW]

i would like to update code so u guys get more game feeling by using the function QueryThreadCycleTime enjoy

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    QueryThreadCycleTime(GetCurrentThread(), &st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    QueryThreadCycleTime(GetCurrentThread(), &ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

I compiled RDTSC with your code, but I didn't notice any changes compared to the original.

Try add SetProcessAffinityMask in first core see if any improvement

Code: Select all

SetProcessAffinityMask(GetCurrentProcess(), 1);

test fix overhead of QueryPerformanceCounter didnt try for long time so give any updates of it

Code: Select all

 LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    1000000 * (ed.QuadPart - st.QuadPart), fq;
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
    

I think it only got worse after that.

[pox02]

i would like to update code so u guys get more game feeling by using the function QueryThreadCycleTime enjoy

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    QueryThreadCycleTime(GetCurrentThread(), &st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    QueryThreadCycleTime(GetCurrentThread(), &ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

I compiled RDTSC with your code, but I didn't notice any changes compared to the original.

Try add SetProcessAffinityMask in first core see if any improvement

Code: Select all

SetProcessAffinityMask(GetCurrentProcess(), 1);

test fix overhead of QueryPerformanceCounter didnt try for long time so give any updates of it

Code: Select all

 LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    1000000 * (ed.QuadPart - st.QuadPart), fq;
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
    

I think it only got worse after that.

i see one last attempt

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    SetPriorityClass(GetCurrentThread(), REALTIME_PRIORITY_CLASS);
    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
    SetProcessPriorityBoost(GetCurrentThread(), 0);
    SetThreadAffinityMask(GetCurrentThread(), 0x1);
    SetProcessAffinityMask(GetCurrentProcess(), 0x0);
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    LONGLONG begin = GetCycleCount();
	Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

[AndreyRGW]

I compiled RDTSC with your code, but I didn't notice any changes compared to the original.

Try add SetProcessAffinityMask in first core see if any improvement

Code: Select all

SetProcessAffinityMask(GetCurrentProcess(), 1);

test fix overhead of QueryPerformanceCounter didnt try for long time so give any updates of it

Code: Select all

 LARGE_INTEGER fq, st, ed;
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    LONGLONG begin = GetCycleCount();
    Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    1000000 * (ed.QuadPart - st.QuadPart), fq;
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
    

I think it only got worse after that.

i see one last attempt

Code: Select all

LONGLONG GetFrequency(DWORD sleepTime)
{
    LARGE_INTEGER fq, st, ed;
    SetPriorityClass(GetCurrentThread(), REALTIME_PRIORITY_CLASS);
    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
    SetProcessPriorityBoost(GetCurrentThread(), 0);
    SetThreadAffinityMask(GetCurrentThread(), 0x1);
    SetProcessAffinityMask(GetCurrentProcess(), 0x0);
    QueryPerformanceFrequency(&fq);
    QueryPerformanceCounter(&st);
    LONGLONG begin = GetCycleCount();
	Sleep(sleepTime);
    QueryPerformanceCounter(&ed);
    LONGLONG end = GetCycleCount();
    return (end - begin) * fq.QuadPart / (ed.QuadPart - st.QuadPart);
}

This version seems to work fine. Happy new year, by the way.

[pox02]

wrong