Hahahaha !!! The fsb amungst all 4 cores? You've got to be kidding me !!! You mean it's qaudpumped, so 266 might be displaying as 1066, and since your ddr2 is doublepumped it might be showing up at half the speed it's actually running at. On a asus mobo there should be a tab called advanced settings though, and then theres something called jumperfree settings.
Using external tools is fake though, overclocking in the bios is 10 times better. And to answer your question, the multiplier is 9, so 2800/9 = 311. Try 333 instead for 3ghz. But only do so if you are using an aftermarket HSF or watch temps like a hawk, on the stock cooler I bet temps will go over 60c easily when put under load.