CMX512-2700C2 + CMX512-3200C2 are both recognized but won't run together?

[live-]

Specs:

 

Chaintech VNf-250 w/ A64 3000+ 754 (newcastle)

eVGA 6800 GT

 

Anyway, I had been running it with one stick CMX512-2700C2 for a while now. I just recently purchased a second stick of CMX512-3200C2. I figured that it couldn't hurt and that the new stick would just downclock to 166 MHz and run in tandem with my older stick of DDR333.

 

Anyway, upon initially installing it, I had the 2700 in DIMM 1 and the 3200 in DIMM 2. The computer booted, but it only recognized the new 3200 stuff, and only 512 MB total. Nvidia System Utility shows both sticks:

 

http://69.137.36.220/ram_problems.jpg

 

I tried manually downclocking to 166 Mhz, increasing the timings, every combination of DIMM slots, updated BIOS...

 

Any ideas as to why these two sticks won't work together?

[CMC_SAVAGE]

In theory it would sound simple enough to set the timings to

2.5-3-3-6 @ 333MHz.

The SPD of the modules are "nearly" the same except for the RAM speed.

You could try bumping the Dimm voltage to 2.7.

There just may be too much of a difference between the two to get them to

work together.

[live-]

In theory it would sound simple enough to set the timings to

2.5-3-3-6 @ 333MHz.

The SPD of the modules are "nearly" the same except for the RAM speed.

You could try bumping the Dimm voltage to 2.7.

There just may be too much of a difference between the two to get them to

work together.

I just tried setting the dimm voltage to 2.7, and still no luck.

 

Do you think I should just go ahead and order another stick of 3200 XMS? I'd assume that two identical sticks would have to work together?

[CMC_SAVAGE]

With the CPU that you have the 2700 isn't doing you justice.

If you want to run 1GB of RAM I'd suggest that you get another stick of the 3200C2.

Better yet, if you can return the stick and purchase a TWINX set you'd be better off.

If you decide to go with another 3200C2 stick, I'd call first and make sure the

stick will be the same REV. as what you have.

It just makes it easier when the sticks are the same.

[live-]

I guess going with a matched-pair set (TWINX) would be the only sure way to avoid further problems. I am ordering all of this off of Newegg, so I would assume it would be difficult to determine exactly which revision I'd be getting if I ordered another stick.

 

Thanks for all of your help, I really appreciate it. ;):

[RAM GUY]

With this platform you really need to use a matched pair of modules. Sorry but that is a limitation of the memory controller in the CPU!