Updating graphics card...

[Meloco]

I was wondering if it is worth upgrading from an HD4850 512MB. After reading some posts on here about gaming on higher res' and needing a 1GB card as standard. I upgraded from a 19" monitor (1280x1024) to a 24" 1920x1200, and was wondering if it's time to update the graphics card too? If so what should I upgrade too, and a little paranoid that my PSU won't be able to handle it. Specs in sig.

PSU currently : Hiper HPU-4M580 Type M CrossFire Certified 580W ATX2.2 PSU - Black

 

[Meloco]

Does the 4850 play games at 1920 with AA and AF ok?

tbh with AA enabled it struggles a bit, so I usually have it off. But i've only recently been playing ARMA2 at this res, which seems to run ok on normal/high settings. Cryostasis and stalker clear sky are very choppy though.

edit: Would the 4890 really be a step up from the 4850? Would a 4870x2 be better (if my psu can handle it) or one of the Nvidia cards?

 

[Meloco]

on the hiper website it says:
+12v 1 (± 5%) 1A - 20A
+12v 2 (± 5%) 1A - 18A

 

[Meloco]

That psu should be ok, but its not great! My PSU has 18A on each rail (three rails), Whats your budget?

Whatever will be a decent PSU. Not concerned on price, as long as the quality is good, and possibly sustainable for an upgrade to an i7 rig somewhere down the line (a year/ 6 months). But obviously don't want to spend the money on something I don't need, e.g. 1000w).