std::this_thread::get_id() vs passing ID

What is the difference between these two codes? What is the best / fastest way. Trying to make my own WM_TIMER thread.

1st: timerThreadProc

with get_id()

DWORD WINAPI timerThreadProc(DWORD dwMilliseconds)
{
    while (!bExit)
    {
        if (std::this_thread::get_id() == hTimer1Thread.get_id())
        {
            // do what ever
            Beep(10000, 100);
        }

        if (std::this_thread::get_id() == hTimer2Thread.get_id())
        {
            // do what ever
            Beep(1000, 100);
        }

        Sleep(dwMilliseconds);
    }
    return 1;
}

2nd: timerThreadProc

without get_id()

#define TIMER1 1
#define TIMER2 2
DWORD WINAPI timerThreadProc(UINT ID, DWORD dwMilliseconds)
{
    while (!bExit)
    {
        if (ID == TIMER1)
        {
            // do what ever
            Beep(10000, 100);
        }

        if (ID == TIMER2)
        {
            // do what ever
            Beep(1000, 100);
        }

        Sleep(dwMilliseconds);
    }
    return 1;
}