كيف يمكن حساب سرعة الاتصال بالانترنت

PHP كود :
var
  Form1: TForm1;
  time:integer;
implementation

{$R *.dfm}



procedure TForm1.btn1Click(Sender: TObject);
var ms:tmemorystream;
begin

ms:=TMemoryStream.Create;
try
IdHTTP1.Get('http://cdn.mirror.garr.it/sf/project/sevenzip/7-Zip/9.20/7z920.exe',ms);
ms.SaveToFile('_file');
finally
  ms.Free;
  DeleteFile('_file')
end;

end;

procedure TForm1.FormCreate(Sender: TObject);
begin

end;

procedure TForm1.IdHTTP1Work(ASender: TObject; AWorkMode: TWorkMode;
  AWorkCount: Int64);
begin
Application.ProcessMessages;
AdvSmoothGauge1.MaximumValue:=(IdHTTP1.Response.ContentLength div 1024);
AdvSmoothGauge1.Value:=AWorkCount div 1024 ;
if time<>0 then

AdvSmoothLabel1.Caption.Text:=FloatToStr((AWorkCount div 1024) div time)+' Kb/sec'  ;
Application.ProcessMessages;

end;

procedure TForm1.IdHTTP1WorkBegin(ASender: TObject; AWorkMode: TWorkMode;
  AWorkCountMax: Int64);
begin
time:=0;
tmr1.Enabled:=true;
end;

procedure TForm1.IdHTTP1WorkEnd(ASender: TObject; AWorkMode: TWorkMode);
begin
tmr1.Enabled:=false;
stat1.Panels[0].Text:='Dowload | Time : '+IntToStr(time)+ ' Sec | Speed : '+ FloatToStr((IdHTTP1.Response.ContentLength div 1024) div time)+  ' kb/sec'
end;

procedure TForm1.tmr1Timer(Sender: TObject);
begin
Inc(time);
end;

end.