1   
2   (* NOTE: this may not work on all computers due to hardware limitations. *)
3   
4   function RDTSC : Int64; assembler;
5   asm
6     db $0F, $31 // opcode for RDTSC
7   end;
8   
9   function RDQPC : Int64;
10  begin
11    //retrieves the current value of the high-resolution performance counter, if one 
12  //exists.
13    QueryPerformanceCounter(result);
14  end;
15  
16  function CPUSpeed : Integer;
17  var
18  f, tsc, pc : Int64;
19  begin
20  //etrieves the frequency of the high-resolution performance counter, if one exists.
21  if QueryPerformanceFrequency(f) then
22  begin
23    Sleep(0);
24    pc := RDQPC;
25    tsc := RDTSC;
26    Sleep(100);
27    pc := RDQPC-pc;
28    tsc := RDTSC-tsc;
29   result := round(tsc * f / (pc * 1000000));
30  end
31  else
32    result := -1;
33  end;