I put a 4800se in a AMD64 at weekend and it ran doom3 really well. (similar to a 4600).
But do bear in mind that they are driectx8 cards and may not run some other games as well as newer directx9 cards.
Given your budget though I'd go for a 4600, untill you spend around the £130 mark the other cards arent much better.
But do bear in mind that they are driectx8 cards and may not run some other games as well as newer directx9 cards.
Given your budget though I'd go for a 4600, untill you spend around the £130 mark the other cards arent much better.