On Sun, Apr 10, 2005 at 09:09:26AM +0000, Brian J. Beesley wrote: > On the other hand, it is well known that modern CPUs can and do "turn off" > unused execution units, with a very significant saving in current. They can > do this because they are based on bipolar logic, which (unlike DRAM) can be > run at low voltage with a slow or zero clock speed without losing data > contents and can therefore be "turned on" again instantaneously when required.
Bipolar logic became obsolete long ago. Modern CPUs are based on CMOS. In fact, I've never seen a bipolar microprocessor. Some of the Pentium processors contain BJTs as well as MOSFETs, but I think they're used for things like amplifiers and PLLs rather than digital logic. In any case, every Intel X86 since the Pentium II seems to have been pure CMOS. Source: http://www.icknowledge.com/history/history.html _______________________________________________ Prime mailing list [email protected] http://hogranch.com/mailman/listinfo/prime
