How to get CPU speed from Delphi 64 bit application (XE5)?

Question

We are in the process of migrating our application suite to 64 bit using Delphi XE5. In our about boxes we display the CPU speed. The routine we currently use is 32 bit assembly and therefore will not compile under 64 bit.

Is there a native way to retrieve CPU speed from within Delphi 64 bit?

Answer 1

If your platform is windows and you want the advertised CPU speed then you can simply check the HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\~MHz DWORD value in the Registry:

program SO21757165;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  Registry,
  Windows,
  System.SysUtils;

function GetCPUSpeed : String;

var
  Reg : TRegistry;

begin
 Reg := TRegistry.Create(KEY_QUERY_VALUE);
 try
  Reg.RootKey := HKEY_LOCAL_MACHINE;
  if Reg.OpenKeyReadOnly('HARDWARE\DESCRIPTION\System\CentralProcessor\0') then
   begin
    Result := Format('CPU Speed is %dMHz', [Reg.ReadInteger('~MHz')]);
    Reg.CloseKey;
   end;
 finally
  Reg.Free;
 end;
end;

begin
  try
    { TODO -oUser -cConsole Main : Insert code here }
    Writeln(GetCPUSpeed);
    Readln;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

EDIT

rewrote above code snippet to a compileable example. This example has been verified in XE7and works in 32bit and 64 bit environments (with UAC enabled)