The guys from VR-Zone heard the ATI X1800XT (R520XT) will be clocked at 650MHz with 1400MHz memory. This in combination with the AMD Athlon64 FX-55 processor should be good enough for 8600 marks in 3DMark05.
If correct, this is almost 1000 marks higher than the GeForce 78000 GTX at 430/1200MHz.
It is certainly interesting to see how the R520XTs in Crossfire performs. There is a 32 pipes version of the R520 as well but it can only be clocked at 520MHz and as a result it will perform lower than the 24 pipes R520XT @ 650Mhz core. Therefore ATi will not release 32pp version until R580 comes along.