I have a HP Pavillion a1512x desktop running @ 2.80 mhz w/4gb memory the graphics is handled by an Intel (r)82945g Intel intergrated (r)82945g chipset family video card. I want to upgrade to a better monitor and this chipset will not handle it so I was wondering if I could upgrade to a ATI Radeon HD 4850 or possibly a XFX HD 577A-ZNDC Radeon 5770. I use this machine mostly for photographic work. I have an empty PCI Express x16 expansion slot.
those cards would be bottlenecked by your cpu and your powersupply would probably not handle those cards. i would take a look on an ati 4670 or 5670. those are low power cards and probably could run on your system.