Thanks for the answers, sorry for not responding sooner.
My 4870 is 1GB, and i play on a 24" monitor with i believe 1920x1200 resolution (cant remember exactly).
My CPU is, for those who wanted to know, is a Intel Dual Core 3.0GHz processor.
My card runs all current games maxed out. It's just that BC2 recommended requirements listed a quad-core cpu as recommended; i dont know, i just feel insignificant without it
that is why i was wondering whether or not to corssfire