Dell 435mt and corsair xms 4gb stick

[dbam987]

Hi, I have a Dell 435 MT and am having a problem with the reported RAM on my machine. The machine originally came with 6x1GB DDR3 sticks which work fine. I recently bought a 4GB Corsair XMS stick to bring the total to 9 GB on my machine. However, Windows 7 and the BIOS report only 4 GB installed. What gives? Do I need to install in pairs the same modules? I thought I could mix 'n match...

 

[jaquith]

Welcome to Tom's Forums!

Déjà vu Dell 435's - http://www.tomshardware.com/forum/281725-30-dell-studio-435t-ocz3p1333lv6gk-voltage-compatibility-issu

The RAM needs to be installed in sets of 3 or worst 2, otherwise you're killing the Tri/Hexa Channel benefits. In your case I'm surprised it posted.

One channel 3x1GB = 3GB, and apparently you got lucky with the first 1GB even being recognized on the Second Channel.

RETURN THE RAM ->RMA. Otherwise Exchange for a Tri Channel {Set} 3X2GB set for 9GB. Most importantly, the NEW RAM MUST match the Type/DDR3, Speed of the 1GB, CAS timings, and Voltage of the 1GB.

 

[dbam987]

Thanks for the quick response. One thing you say above is that my machine shouldn't have posted when having 5x1gb sticks + 1x4gb stick? For the time being, I'm going to try several combinations, including the following to see what I get. There was one boot that actually did show the whole 9gb but the next boot showed 5gb and one more reboot showed 4gb. Maybe Dell's mobo's don't like mixed memory module sizes...

 

[jaquith]

^Post/Unstable/BSOD - It running + every Permutation won't correct the underlying problems. You may try 1GB slots 1/3/5 and 4GB slot 2.

Trust me, get a 3X2GB 'Matching' {set} to your 3X1GB {set}; use CPUz if you are uncertain "what" you have installed, or pull a stick and look-up the Part-Number. http://www.cpuid.com/softwares/cpu-z.html

 

[dbam987]

Best answer selected by dbam987.