I wouldn't go anywhere near ATI if you want to use Maya. Maya generally runs bad with ATI. Radeons are gaming cards to begin with, so they're no built for running OpenGl very well. That said, a lot of people use gaming cards (mostly geforce, ATI really doesn't like Maya) and they have no issues.
And just to make the point about how bad ATI are with Maya, I recently purchased an ATI FirePro card from them- a workstation card specifically designed to handle OpenGL and 3D/CAD applications, and Maya was unusable on in.
So, to be honest, I would rather buy an Nvidia (or laptop with Nvidia) for £500 over the equivalent ATI (or laptop with ATI) for £200!!!
So, in short, no I don't think ATI are very good cards for running Maya.
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