Crossfire setup

When it comes to CF, i suggest u to CF 2 identically cards, so u already have 4850 then add more one 4850, u will get a high jump performance with that setup...
Make sure your PSU can handle that cards...  

I agree w/ what ^ guy said

You can CF a HD 4850 with HD 4870X2/4870/4850 and 4830 so you can't CF it with a HD 4650.
Between them the best thing is to CF a HD 4850 with another HD 4850 since they are the same card

Thanks everybody, y'all have just confirmed what I thought, just checking with the experts...the 4650 was a freebie!!!!