Memory Problem In Dell 9100 Desktop

Hey, I'm a longtime fan of this site, finally asking a question myself.


I bought this computer from a friend, and initallly everything wasorking fine. I installed all of the recommended updates to my Dell Studio XPS 9100, including a bios update, and at some point after the bios update, my ram showed as 2 gig when 6 gigs are installed physically. I tried reorder the ram, and the result was the same in a combos/positions: the ram appears functional but only one chip seems to be in use by the bios/system. I would like to upgrade this computer with more ram, but need to solve this problem with the current ram before I spend anymore on this computer. I note that I'm fairly sure all the DDR3 chips are working individually, and also that I wasn't able to downgrade to the original bios version, the installer from dell won't let you downgrade your bios.
Please help me allow my system to use it's full installed amount of ram, seriously, @ 2G/RAM the machine is awfully slow.

Help me Obe-Wan your my only hope!

Here are the specs for my machine:

OS Name Microsoft Windows 7 Ultimate
Version 6.1.7601 Service Pack 1 Build 7601
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name DAVID-PC
System Manufacturer Dell Inc.
System Model Studio XPS 9100
System Type x64-based PC
Processor Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz, 2801 Mhz, 4 Core(s), 8 Logical Processor(s)
BIOS Version/Date Dell Computer Corporation A04, 10/21/2010
SMBIOS Version 2.6
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume1
Locale United States
Hardware Abstraction Layer Version = "6.1.7601.17514"
User Name David-PC\David
Time Zone Eastern Daylight Time
Installed Physical Memory (RAM) 2.00 GB
Total Physical Memory 1.99 GB
Available Physical Memory 645 MB
Total Virtual Memory 3.98 GB
Available Virtual Memory 1.53 GB
Page File Space 1.99 GB
Page File C:\pagefile.sys

 

Just for clarification, all 6GB was properly identified before, right? And is it 64-bit Windows?

How is your 6GB configured? Is that 3 x 2GB or, 1 x 2GB + 1 x 4GB? If 3 x 2GB, does it work with just 2 sticks installed? If 2 + 4GB, does it work with just the 4GB installed?

You need to be totally sure. I recommend MemTest86. Allow the diagnostics to run for several passes or even overnight. You should have no reported errors. If MemTest86 does not see the full amount, you need to test each stick separately.

And did you buy more RAM or did you buy if from your friend with 6GB already installed? If you bought some, how did you ensure it was the right and compatible RAM?

 

thanks, I ran Memtest86 with no errors, via usb drive as instructed by Memtest86 docs, but Memtext only saw 2 gigs of my total of 6 gigs. my physical ram, sorry I didn't post more specifically, are 3 X 2G sticks, the computer will not run unless all the sicks, or at least 2 of the three sticks are inserted in certain slots. I am attaching a picture of the very odd slot arrangement in this machine, look at the pic and notice the ram slot numbers 1-6 are rearranged 4, 1, 5, 2, 6, 3 as labeled on the motherboard.

I got the computer used and at the time, the 6 gigs were working, I guess the 6 gig ram sticks (3) were installed in the factory. I did not add these components.

I tried rearranging the ram, and noticed that there are 'pink ' and ''blue' slots of identical shaped ram slots, and the blue ones are the only that have worked

 

Well if you can pick any 2 of the 3 sticks and they work, then swap in the 3rd stick and it still works, that points to the motherboard. Your only recourse for acceptable performance may be to install 2 x 4GB sticks, if your board supports them.