Mixing Memory - How It Works

At the minute i have 2 sticks of crucial PC2700 256mb cas 2.5. I am running my signature rig at stock speeds and want to upgrade to 1gb ram. As i want to upgrade to A64 in the future i bought some PC3200 with the intention of the mixing it with my current ram. I am not bothered at running the PC3200 at 2700 speeds, but what i was wondering is this.

PC2700 CAS 2.5, PC3200 CAS 3.0

Does it make any difference to which slots i put the memory in. i.e. does the memory in slot 1 get used first, then slot 2 and so on therefor e am i better off leaving the CAS 2.5 as the first port of call - or does it not make any difference?

afaik, the slots make no difference... It's Random Access Memory, so I don't think that one stick fills up first, then another...

But anyway, if the PC3200 only runs at CAS 3.0 you'll have to run the whole lot at that speed, you can't set each memory slot seperately.

TBH the PC3200 should be fine at CAS 2.5 if you're only running it at PC2700 speeds. It might be fine at PC3200 speeds as well.... you can run Memtest86+ or Prime95 to make sure.

I can't see your sig for some reason.

Sorry get confused between this and another forum i subscribe to - sig rig is nothing fancy MSI KT6 Delta - XP2800+ @ stock, 512mb crucial PC2700 + 512mb Nanya PC3200, 9600XT.

Anyway as you can see i have the new mem installed with old and i have to say what a difference - I didn't reallly think i would notice much of a difference as even when i had 512 it wasn't being fully utilized.

Thanks for the advice - don't usually get too many replys to my threads - maybe i'm just asking completely stupid questions that don't deserve and answer