hey ,
i have got the x1900 pro 512mb
it workt fine here , nice fps, good card.
i also havea 300 W power...
so it is possible,
but for example: i know that M.Hoekstra (teammate) is using a x1900 pro 256 mg , but he had to buy a 500W powersurply,
his 300W wasnt engough
i think that its because he have a dual core amd and i have got a single amd. the other stuff of my system is the same.
greets,
Reintjan