Join Date: Jan 2007
Location: The Netherlands
Re: Lets talk about ram....
As said, it depends on the motherboard (well mostly the chipset, somewhat the BIOS I guess).
I have an Asus P5B Deluxe motherboard with Intel P965 chipset, which is very clever about memory. It is able to use some memory in dual channel, and the 'remainder' in single channel mode.
I run 3 GB myself, with 2x1 GB sticks and 2x512 MB sticks, and it can run all of that completely in dualchannel, I just have to stick them into the right slots.
Some boards/chipsets are more picky, and will only run dualchannel if they can run ALL banks in dualchannel.
As for different brands/types of memory... Sometimes it works, sometimes it doesn't. It mainly has to do with the addressing. Some sticks have 8 chips on them, others have 16 for example (usually double-sided). It's hard for the memory controller to address such different memory sticks together.
As long as they're physically the same type, the actual brand doesn't matter. Speed doesn't even have to match, you'll just take the lowest common denominator. Faster memory can always run at lower speeds.