the memory isnt the only thing wrong with the x1600 after reading a bunch of reviews it would appear the ati r500 fudd continues. Much like the x1900 series which they claim has 48 pixel units at heart its still a 16 pipeline card. The x1600 claims to have 12 but its really only a 4 unit device which means my 2 1/2 year old 9800xt is still quicker than it.
http://www.anandtech.com/video/showdoc.aspx?i=2552&p=9
that shows how much of a dog the x1600 is (note thats the faster xt version!)