var
 Status : TMemoryStatus;
begin
 Status.dwLength := sizeof( TMemoryStatus );
 GlobalMemoryStatus( Status );
...

unit MemForm;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 Grids, ExtCtrls, StdCtrls;
type
 TForm1 = class(TForm)
  StringGrid1: TStringGrid;
  Timer1: TTimer;
  StringGrid2: TStringGrid;
  BtnString: TButton;
  BtnStringList: TButton;
  BtnForm: TButton;
  BtnBigAlloc: TButton;
  BtnSmallAlloc: TButton;
  procedure FormCreate(Sender: TObject);
  procedure Timer1Timer(Sender: TObject);
  procedure BtnStringClick(Sender: TObject);
  procedure BtnStringListClick(Sender: TObject);
  procedure BtnFormClick(Sender: TObject);
  procedure BtnSmallAllocClick(Sender: TObject);
  procedure BtnBigAllocClick(Sender: TObject);
 private
  procedure UpdateStatus;
 public
  s: string;
  sl: TStringList;
  f: TForm;
 end;
var
 Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.UpdateStatus;
var
 MemStatus: TMemoryStatus;
 HeapStatus: THeapStatus;
begin
 MemStatus.dwLength := sizeof(TMemoryStatus);
 GlobalMemoryStatus(MemStatus);
 with MemStatus do
 begin
  // load
  StringGrid1.Cells[1, 0] := IntToStr(dwMemoryLoad) + '%';
  // RAM (total, free, load)
  StringGrid1.Cells[1, 1] := FloatToStrF(
  dwTotalPhys / 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid1.Cells[1, 2] := FloatToStrF(
  dwAvailPhys / 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid1.Cells[1, 3] := IntToStr(100 -
  dwAvailPhys div (dwTotalPhys div 100)) + '%';
  // page file (total, free, load)
  StringGrid1.Cells[1, 4] := FloatToStrF(
  dwTotalPageFile / 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid1.Cells[1, 5] := FloatToStrF(
  dwAvailPageFile / 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid1.Cells[1, 6] := IntToStr(100 -
  dwAvailPageFile div (dwTotalPageFile div 100)) + '%';
  // page file (total, used, free)
  StringGrid1.Cells[1, 7] := FloatToStrF(
  dwTotalVirtual / 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid1.Cells[1, 8] := FloatToStrF(
  dwAvailVirtual / 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid1.Cells[1, 9] := FloatToStrF(
  (dwTotalVirtual - dwAvailVirtual) / 1024,
  ffNumber, 20, 0) + ' Kbytes';
 end; // with MemStatus
 HeapStatus := GetHeapStatus;
 with HeapStatus do
 begin
  StringGrid2.Cells[1, 0] := FloatToStrF(
  TotalAddrSpace div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 1] := FloatToStrF(
  TotalUncommitted div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 2] := FloatToStrF(
  TotalCommitted div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 3] := FloatToStrF(
  TotalFree div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 4] := FloatToStrF(
  TotalAllocated div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 5] := IntToStr(
  TotalAllocated div (TotalAddrSpace div 100)) + '%';
  StringGrid2.Cells[1, 6] := FloatToStrF(
  FreeSmall div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 7] := FloatToStrF(
  FreeBig div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 8] := FloatToStrF(
  Unused div 1024,
  ffNumber, 20, 0) + ' Kbytes';
  StringGrid2.Cells[1, 9] := FloatToStrF(
  Overhead div 1024,
  ffNumber, 20, 0) + ' Kbytes';
 end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
 StringGrid1.Cells[0, 0] := 'Memory load';
 StringGrid1.Cells[0, 1] := 'Physical memory';
 StringGrid1.Cells[0, 2] := 'Free physical memory';
 StringGrid1.Cells[0, 3] := 'RAM load';
 StringGrid1.Cells[0, 4] := 'Maximum size of paging file';
 StringGrid1.Cells[0, 5] := 'Available in paging file';
 StringGrid1.Cells[0, 6] := 'Paging file load';
 StringGrid1.Cells[0, 7] := 'Virtual address space';
 StringGrid1.Cells[0, 8] := 'Free in address space';
 StringGrid1.Cells[0, 9] := 'Used address space';
 StringGrid2.Cells[0, 0] := 'Available address space ';
 StringGrid2.Cells[0, 1] := 'Uncommitted portion';
 StringGrid2.Cells[0, 2] := 'Committed portion';
 StringGrid2.Cells[0, 3] := 'Free portion';
 StringGrid2.Cells[0, 4] := 'Allocated portion';
 StringGrid2.Cells[0, 5] := 'Address space load';
 StringGrid2.Cells[0, 6] := 'Total small free blocks';
 StringGrid2.Cells[0, 7] := 'Total big free blocks';
 StringGrid2.Cells[0, 8] := 'Other unused blocks';
 StringGrid2.Cells[0, 9] := 'Total overhead';
 UpdateStatus;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
begin
 UpdateStatus;
end;
procedure TForm1.BtnStringClick(Sender: TObject);
begin
 // 10 megabytes
 SetLength(s, 10000000);
 UpdateStatus;
end;
procedure TForm1.BtnStringListClick(Sender: TObject);
var
 I: Integer;
begin
 sl := TStringList.Create;
 // add one thousand strings
 for I := 0 to 1000 do
  sl.Add('hello');
 // destroy some of them
 for I := 300 downto 1 do
  sl.Delete(I * 3);
 UpdateStatus;
end;
procedure TForm1.BtnFormClick(Sender: TObject);
var
 I: Integer;
begin
 // create ten forms
 for I := 1 to 10 do
  F := TForm.Create(Application);
 UpdateStatus;
end;
procedure TForm1.BtnSmallAllocClick(Sender: TObject);
var
 P: Pointer;
begin
 GetMem(P, 100);
 Integer(P^) := 10;
 UpdateStatus;
end;
procedure TForm1.BtnBigAllocClick(Sender: TObject);
var
 P: Pointer;
begin
 GetMem(P, 100000);
 Integer(P^) := 10;
 UpdateStatus;
end;
end.