C# - How do you get total amount of RAM the computer has?

Question

I'm wanting to get the total amount of RAM my computer has using C#. Using the PerformanceCounter I can get the amount of Available ram, by setting:

counter.CategoryName = "Memory";
counter.Countername = "Available MBytes";

But I can't seem to find a way to get the total amount of memory. How would I go about doing this?

Update:

MagicKat: I saw that when I was searching, but it doesn't work - "Are you missing an assembly or reference?". I've looked to add that to the References, but I don't see it there.

Answer 1

.net has a limit to the amount of memory it can access of the total. Theres a percentage, and then 2 GB in xp was the hard ceiling.

You could have 4 GB in it, and it would kill the app when it hit 2GB.

Also in 64 bit mode, there is a percentage of memory you can use out of the system, so I'm not sure if you can ask for the whole thing or if this is specifically guarded against.

From its perspective, total is what its allowed to have.

Answer 2

Add a reference to Microsoft.VisualBasic and a using Microsoft.VisualBasic.Devices. The ComputerInfo class has all the information that you need.

Answer 3

You could use WMI. Found a snippit.

Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" _ 
& strComputer & "\root\cimv2") 
Set colComputer = objWMIService.ExecQuery _
("Select * from Win32_ComputerSystem")

For Each objComputer in colComputer 
  strMemory = objComputer.TotalPhysicalMemory
Next

Answer 4

The p/invoke way EDIT : Changed to GlobalMemoryStatusEx to give accurate results (heh)

  [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
  private class MEMORYSTATUSEX
  {
     public uint dwLength;
     public uint dwMemoryLoad;
     public ulong ullTotalPhys;
     public ulong ullAvailPhys;
     public ulong ullTotalPageFile;
     public ulong ullAvailPageFile;
     public ulong ullTotalVirtual;
     public ulong ullAvailVirtual;
     public ulong ullAvailExtendedVirtual;
     public MEMORYSTATUSEX()
     {
        this.dwLength = (uint)Marshal.SizeOf(typeof(NativeMethods.MEMORYSTATUSEX));
     }
  }


  [return: MarshalAs(UnmanagedType.Bool)]
  [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
  static extern bool GlobalMemoryStatusEx([In, Out] MEMORYSTATUSEX lpBuffer);

Then use like:

ulong installedMemory;
MEMORYSTATUSEX memStatus = new MEMORYSTATUSEX();
if( GlobalMemoryStatusEx( memStatus))
{ 
   installedMemory = memStatus.ulTotalPhys;
}

Or you can use WMI (managed but slower) to query "TotalPhysicalMemory" in the "Win32_ComputerSystem" class.

Edit fixed code per comment from joel-llamaduck.blogspot.com

Answer 5

Add a reference to Microsoft.VisualBasic.dll, as someone mentioned above. Then getting total physical memory is as simple as this (yes, I tested it):

static ulong GetTotalMemoryInBytes()
{
    return new Microsoft.VisualBasic.Devices.ComputerInfo().TotalPhysicalMemory;
}

Answer 6

If you happen to be using Mono, then you might be interested to know that Mono 2.8 (to be released later this year) will have a performance counter which reports the physical memory size on all the platforms Mono runs on (including Windows). You would retrieve the value of the counter using this code snippet:

using System;
using System.Diagnostics;

class app
{
   static void Main ()
   {
       var pc = new PerformanceCounter ("Mono Memory", "Total Physical Memory");
       Console.WriteLine ("Physical RAM (bytes): {0}", pc.RawValue);
   }
}

If you are interested in C code which provides the performance counter, it can be found here.