QueryPerformanceCounter

Maybe the one microsecond timestamp is too long for your program. You can access the Windows API Performance Counter using code such as shown below. Note that this API may not be as reliable as you might hope. For more information see http://www.virtualdub.org/blog/pivot/entry.php?id=106

unit Unit1; 
{$mode objfpc}{$H+}
interface
uses
 Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
 StdCtrls, Windows;
type
 { TForm1 }
 TForm1 = class(TForm)
   procedure FormClick(Sender: TObject);
 private
   { private declarations }
 public
   { public declarations }
 end; 
var
 Form1: TForm1; 
implementation
{ TForm1 }
procedure TForm1.FormClick(Sender: TObject);
var
 PerformanceCounter: int64;
 PerformanceFrequency: int64;
begin
 if QueryPerformanceFrequency(PerformanceFrequency)
    AND QueryPerformanceCounter(PerformanceCounter)
   then ShowMessage(
                    'Freq:'+IntToStr(PerformanceFrequency)
                    +', Counter:'+IntToStr(PerformanceCounter)
                    )
   else ShowMessage('Sorry, performance counters not supported.');
end;
initialization
 {$I unit1.lrs}
end.