I'm looking for a new mid-range card and was wondering how the x2900 xt compared to the older x1950 xt.  I don't see myself upgrading to vista any time soon if at all with this computer. 

I currently have an ati x1650 pro w/256 mb.  I'd like someting a little faster with double the memory.  My computer is an original Dual Core Pentium D 3.2 Ghz and 3gb of ram so I don't think I need anything faster than the x2900 xt.  I currently have a 305W PSU which I'm upgrading to 470W - it's a Dell what can I say 

Any advice on these two cards or any other equivalents would be welcomed.