Radeon X2800XTX will work at 750MHz/2200MHz
 

$550 for this puppy, high end all the way.

"THE RADEON X2800XTX will work at 750MHz core clock and the GDDR 4 memory is clocked at 2200MHz. This is how the R600XTX will be known from now on. As always, these clocks are close to final but ATI can still change them till the launch date sometime in March.

http://www.theinquirer.net/default.aspx?article=37638