I built my system a couple months ago and just NOTICED that all of my RAM does not show up in my msinfo or dxdiag...  and I can't seem to get a straight answer ANYWHERE.

I have 4 GB installed on 32 bit Vista (yeah i KNOW...ouch.)  .. and it all shows up in BIOS.

Only 2.8 shows up...

I understand my GPU USES up RAM but its only a 512mb card, so shouldn't it be around 3.5GB? Where's the other GB?

Here is a copy of my dxdiag...

  ------------------
System Information
 ------------------
Time of this report: 5/16/2008, 20:16:14
       Machine name: DAN-PC
   Operating System: Windows Vista™ Ultimate (6.0, Build 6001) Service Pack 1
           Language: English (Regional Setting: English)
System Manufacturer: NVIDIA
       System Model: 132-CK-NF78
               BIOS: Phoenix - AwardBIOS v6.00PG
          Processor: Intel(R) Core(TM)2 Duo CPU     E8400  3.00GHz (2 CPUs), ~3.8GHz
             Memory: 2814MB RAM
          Page File: 1458MB used, 4379MB available
        Windows DIR: C:\Windows
    DirectX Version: DirectX 10
DX Setup Parameters: Not found
     DxDiag Version: 6.00.6001.18000 32bit Unicode

---------------
Display Devices
---------------
        Card name: NVIDIA GeForce 8600 GTS
     Manufacturer: NVIDIA
        Chip type: GeForce 8600 GTS
         DAC type: Integrated RAMDAC
   Display Memory: 1648 MB
 Dedicated Memory: 497 MB
    Shared Memory: 1151 MB
     Current Mode: 1680 x 1050 (32 bit) (60Hz)
          Monitor: SyncMaster 226BW(Digital)
 
      DDI Version: 10

Check this site:  http://www.crucial.com/kb/answer.aspx?qid=4251If it's not 64bit Vista it will only recognise about 3.1MG of RAM...
Stop losing sleep over it even though you paid for 4G.If it's not 64bit Vista it will only recognise about 3.1MG of RAM...

My link made the same statement.  It just took it 2 more paragraphs to say so.