DDR400 dual channel memory...

[jbenj01]

I have 1G of some Crucial DDR400 CL3 memory (Micron) installed in my new system.. Well, without realizing, i just bought another 1G of Micron/Crucial DDR400 memory but it's CL2 ..

Any ill-effects/consequences of running different CL timing memory in the same system?

[joshyg2]

If your unsure, try running both banks of RAM at CL3. But, if your sure that the other stick is able to run at CL2 then run it so as long as both sticks are timed at whatever both sticks are capable of.

[jbenj01]

Is there a noticeable difference in performance between running CL3 vs. CL2 ?? Not quite sure what the heck that means.. ??

[Sastraxi]

CAS Latency of 3 is basically the worst you can get... most ram runs at 2 or 2.5 CL. It means... *gets out page filled with techno-jumble*

Basically it's the ratio of the memory clock to the system clock.
http://www.dewassoc.com/performance/memory/cas_latency.htm

And apparently 2.5 is rounded up to 3... =/

[Solo]

It also depends on which front side bus you are running.

For example I have kingston DDR400 Valve RAM which is rated at CL3,
however that is for running at 200 fsb.
If you use a lower fsb it can however run at CL2.5
I can run mine at CL2.5 from 166 - 180 fsb and it is stable. But anything higher than that and I have to increase the latency to CL3.

As for above I've never tried that, but I would imagine it will only run at the lower speed of the two. Fast RAM can perform slower ie CL3
but CL3 RAM ain't gonna perform at CL2 - successfully.

Personally I'd sell the CL3 and get more CL2.