Can 256 MB be connected with 512 MB

[photon]

I am having 865GBF motherboard. Which is having 4 RAM slots. Presently i am having 2 256MB DDR 2 400 RAM. Total512 MB . Can i connect another single block 512 MB RAM. Is there will be any compatibility problem due to 256 and 512 difference?

[The_Devil_Himself]

^^no you can safely connect them.They should preferably have the same frequency.

[shady_inc]

For the moment,remove both 256 mb sticks and run your PC on single 512 mb stick.Then,you can sell off those two sticks to get a new same frequency 512 mb RAM.