Originally Posted by JMJ_coder
I don't know if they already have a technique for this, but it would be nice if one could completely shutdown unused cores and maybe even underclock the used core when computing power is not needed and bring them back online during the few times you'd need that extra computational ability (the old 80/20 rule makes another visit) -- and have it do this on the fly.
Many currently does something similar, but not that powerfull (like switching off the cores). Mine Intel Core 2 Quad Q6600 without overclockded when idle uses 6 ratio (1.6GHz) with lowered Vcore for CPU, if loads goes higher some cores get 9 ratio (2.4GHz) with higher voltage.
AMD Barcolona (K10) cpus also have similar features, each core can have its own ratio and the whole cpu can have lowered Vcore voltage at a time, there are several steps in tha cou depends on load, checkWikipedia for details.