procedure TForm1.Button3Click(Sender: TObject); 
var 
  PerfFreq, StartTime, CurrentTime: int64; 
begin 
  if QueryPerformanceFrequency(PerfFreq) then 
  begin 
    QueryPerformanceCounter(StartTime); 
    // ----------------------------------------- 
    // hier laufen die zu messenden Aktionen 
    // z.B.: 
    sleep(250); 
    // ----------------------------------------- 
    QueryPerformanceCounter(CurrentTime); 
    Label1.Caption := FormatFloat('Dauer: 0.000000 s', 
      (CurrentTime - StartTime) / PerfFreq); 
  end else 
    Label1.Caption := 'Hardware-Voraussetzung fehlt'; 
end;