you do need a new mobo if u dont have pci-i thats old school : D...but you will see a HUGEEEE improvement if u had a better mobo and processor...kuz its bnecking...so you probably will not see any improvement..maybe just a little but it will bneck.
lol ps3 has 2 excusives left
i say go and get a wii i love it =D
but 360 all the way
ps3 has nothing that 360 doesnt have
besides a slight power edge and blueray and a 300 buck bigger price range