xfire in a old + low end card like 5670 is so useless i cant begin to explain,
how low long will u use that 2 more years?
by that time 5000 series will be ancient!!
so the 5670 is just out of the window.
and if u want a good gaming experience in 1080p or even 900p might as well throw the 650 too!
do u know the gtx 650 is the SLOWEST gtx card sold??
it was supposed to be as good as the 550ti but 550ti is faster and around the same price.
if u want a decent gaming experience atleast get a 7770 ~110$
or if u absolutely cant up your budget just get a 7750 atleast u'll save on PSU