i just got an asus HD7770. i got it because it is a newer generation card, uses less power then the geforce 5 series and will allow me to use 2 monitors with one card unlike the geforce 5 series where you would need an SLI setup to use more than 2 monitors.
although if the 660 was out i would have gotten that instead of it.i never did trust or hear good things about ATI drivers. i find the latest cat drivers have a few quirks. nothing major just little annoyances.
Sorry I. A bit of a noob when it comes to this, I don't think I have a power supply problem when it come down to it ( this build would have a 700 watt power supply) so I was kind of confused about what you said. So do you think he GeForce gtx 550 to would work better or on par with your radeon 7770? I would love a reply.