Recently got my hands on a Watt meter, so thought I'd do a little experiment. How much power can be saved by disabling a core in this laptop:
CPU: Core2Duo at 2.0Ghz down clocked to 1.0 GHz
Cores: 2
CPU load: 100% (playing a movie and doing other tasks to ensure load remains constant at/near 100%)
Battery: Removed
Wi-Fi: Downloading large file at near max speeds
Results before: 38.5W max
After 1 core disabled: 33.5 max
And because I down clocked my laptop to half speed, the difference would have been 10W!
(BTW, this is only useful if having longer uptime is more important than performance)
CPU: Core2Duo at 2.0Ghz down clocked to 1.0 GHz
Cores: 2
CPU load: 100% (playing a movie and doing other tasks to ensure load remains constant at/near 100%)
Battery: Removed
Wi-Fi: Downloading large file at near max speeds
Results before: 38.5W max
After 1 core disabled: 33.5 max
And because I down clocked my laptop to half speed, the difference would have been 10W!
(BTW, this is only useful if having longer uptime is more important than performance)