I see on the Udoo shop it says 2.56Ghz but on Intel's site it says 1.6Ghz Base clock speed and 2.56Ghz Burst. Is the actual clock speed of the Udoo x86 1.6Ghz?
Seems to me the answer is in the question .... On-demand (governor) clock speed from 1.6Ghz base on idle and 2.56Ghz @ full load?
1.6 when it doesn't need a lot of power. 2.56 in stressed conditions. It depends on the process that you want the board to execute. I don't know if you can force the board to go in burst mode by disabling the energy-saving features, I suppose you can.