In Sandra multimedia benchmark Agena / Barcelona K10 2.5 GHz scores over 400.000 it/s (instructions / second) in integer test and about 300.000 it/s in floating point test. Yeah there are some Agena / Barcelona parts runing at 2.5 GHz at press time and we got the chance to share the scores with the world. 

Intel's fastest QX6800 Quad core at 3 GHz scores about ~300.000 it/s in integer and ~180.000 it/s in floating point test.

So at least in multimedia stuff and this synthetic benchmark AMD's native quad core is 33.3 percent faster than Intel's fastest Quad core, while in the floating calculations it is a massive 66 percent faster.

The QX6850 with FSB 1333 might improve the situation a bit, but it won't be enough save the day. Intel needs to go much higher than 3 GHZ to match the 2.5 GHz K10 part.