combining memory

im going to be getting a used asus p5kpro that has (1) 2gb stick of crucial 800mhz ddr2 cas 5 ram installed. i want to upgrade to at least 4 gigs ram. is it okay to mix and match brands, or stick with same brand, and if i stick with crucial, can i mix and match models or get the same as the one currently installed.

thanks

in general you can mix and match just fine with different brands whether or not they have the same ics.. even different speeds and cas latencies can often be mixed. it can be hit or miss though so be prepared if things dont work out. personally id just get any other 800 cl5 2gb.. should be ok

You can mix as long as specs match for the most parts. There is a slight risk of incompatibility, so might want to just get a 2x2 GB kit, it's 20-50$ for DDR2 800 kits anyways. If you're using a 64-bit OS, then go ahead and try if it works with all 6 GB installed, too.