Where's my RAM?

pmed · Joined: Jan 11, 2003 Posts: 39 Location: Redlands, CA

Howdy,
I recently put new ram in my Dell SC430 PowerEdge.
It was a matched set of 2gb PC 4200 DDR 533mhz ram (total of 4gb).
When I go to My Computer -> Properties it only reports 3.75 gb of RAM.
Any ideas as to why that would be? I don't think it would be using .25gb for video memory and even if it was wouldn't it be showing up any way?

Any ideas?

Thanks
Paul

zlim · Joined: Mar 11, 2005 Posts: 2635

32 bit versions of windows can not recognize 4 GB of RAM. It is the architecture of windows; you can't change this.
64 bit versions of windows will recognize up to 8GB of RAM, provided the motherboard supports it.

http://www.fnode.com/2007/12/4gb-ram-on-32-bit-operating-system/

drwho07 · Joined: Nov 29, 2007 Posts: 1546 Location: Central FL, USA

Ram is addressed, within a computer in Hexadecimal.

With just 32 bits to address the ram, your PC can only address just so much.
Like zlim said. (it's a little OVER 3 gig's)

When you advance to a 64 bit OS (requiring a 64 bit processor) then and only then will you see the entire 4 gigs. (and a lot more)

But four gigs is the OPTIMUM ram for any 32 bit system and you can get it with just two DIMMS. It's cheaper that way.
Pretty cool, eh?

Enjoy!

Doc Cool

system001 · Posted: Sat Feb 21, 2009 10:19 am Post subject:

Are you running XP or Vista because after SP1 for Vista it will read all of the ram you have at least up to 8 gigs. Microsoft has also removed the 4096 megabyte pagefile limitation in Vista as of sp1. What is most likely happening is some program is reserving that part of your memory for it's use if you are running Vista. My roommate is currently running 5 gigs of ddr2 6400 and it all shows in system properties. I am running 3 gigs of ddr2 6400 with a pagefile of 12288/12288. if you are still on XP i would recommend that you at least Switch to Vista SP1 or wait til later this year for Windows 7. Smile