Three versions of ATI's X700 expected
 

The flagship X700XT will rock with a 500MHz core and will use 1000MHz memory just like Nvidia's 6600GT. You know that you cannot judge the speed from the clock as both chips work differently, but we know that the ATI chip will score approximately 8000 in 3Dmark03 - just as much as Nvidia scores at this test.

http://www.theinquirer.net/?article=18233