you can do a lot of things with easytune. conventionally speaking, all you can hope to do is raise the FSB in order to raise the CPU speed, adjust the memory to keep it within spec, and you should be able to increase/decrease the voltage too.
The ES2L BIOS contains all of these tools as well and it is much more reliable for you to use that instead. You should be able to get close to 3.8 GHz in easytune without changing the voltage too much, but it could crash. Easytune is not a program I would use to "lock in" an overclock. I would use the BIOS. The ES2L is not a bad entry level board. I have done well over 430 MHz FSB on this board.
The idle multiplier for your chip is 6, and 6*333 MHz = 2 GHz. You will never see your CPU running at full speed unless it is actually doing work while you are observing it.