They don't have to be the same size, but they should be the same speed, which they are. Put the 512 stick in the 1st mobo slot.Quote from mktman:
Should have said can I have 512 PC800 and 256 PC800 modules in the machine at the same time or do the modules have to be exactly the same?
thx.
Quote from Jayford:
Hey guys,
I'm adding some Ram to my system and was wondering why I should have the same size in each of my two banks. My system (Dell Dimension 4400) only takes two chips. I have 256MB in it now and wish to add 512. Does it really matter if the sizes are different?
If so, should I put the big one in the first bank?
And finally, do I need to change anything in the BIOS or system somewhere for caching, etc. Or, do I just plug the thing in and go.
BTW, I run Win XP Home edition.
Thanks,
Jay

Quote from canyonman00:
Excuse me for being a tech here, but hopefully you have looked into what your machine can and can't do. You don't just arbitrarily decide that you'd like to run a gig of DDRAM because you want to. Your machine must be able to handle it.![]()