2600+ vs. 2800+: What's the Difference?

In the mobile XP line, both the 2600 and 2800 have a default 133MHz bus and both supposedly run at 2.08GHz. Both have same 512K cache and Barton core. Only difference is the 2800+ has a vcore of 1.65v against the 1.45v of the 2600. So if they run at the same clock speed, and have the same cache and core, why is the 2800 supposedly comparable to a 2.8GHz P4 and the other a 2.6GHz P4? What about the 2800+ makes it faster?

Er I dont think they run at the same frequency must be a typo from wherever you have seen that. Either that or you have confused the XP2800 mobile with its desktop version which does run at 2.08GHz at 166FSB.