The 4650 is also not listed as compatible with the 5520G. Even worse, all known 4650s are MXM-in-shape-only cards, while 9600M GS is a true MXM card, meaning you can't resolve pontential incompatibilities with a BIOS update for a 4650.
Hey NetRolller -Thanks for all the awesome info you dispense! I read through all 200+ pages of the "MXM Models and Cards" thread, but haven't seen any conclusive info on 4650 into aspire 5520g.
I know the 9650m gt is workable, and possibly the 240m, but the sweet spot price/performance-wise looks to be the 4650 (at least here in beijing).
I saw a 3650 install went ok on some .cz site (not listed as compatible via the main mxm thread) After a quick search, it just looks like nobody has tried it, right?