I have heard some sites say it will use GDDR4 as well as clock speed boast on the core or is it just mainstream part. It would make sense if r590 is to combat G71 / ATI already stated that the r520 was not meant to combat the GTX 512 making it the r580 job so what does this leave for the shrink? This would also make sense because of 1450/1550 memory they are using on x1900XT(X) when it should be easy for them to make it to 1600 on the high end like they did with x1800xt OC. It looks like the refresh wars have just begun if you ask me.