System Power Consumption

The four result values are as following:

• AMD Cool'n'Quiet / Intel SpeedStep: Windows Vista with Aero off, sitting at the desktop (1920x1080 32-bit) all windows closed, drivers installed. Processors have their power saving technology enabled, left in idle until power draw is stable.
• Idle: Windows Vista with Aero off, sitting at the desktop (1920x1080 32-bit) all windows closed, drivers installed. Processors have their power saving technology disabled, left in idle until power draw is stable.
• Load: Prime95 is used to increase load on all available cores and measurements are taken when power draw is stable.

Surprisingly single core CPUs aren't that efficient when idling at the desktop. This can be explained with the higher "idle" load that Windows puts on just one core, but when under 100% load, the Sempron consumes 30 W less than the Dual Core Athlon II X2 240 and is on par with Celeron 430.



We checked the undervolting capabilities too. As it turns out, our sample can maintain stable operation at 2.70 GHz with just 1.05 V core voltage, while stock core voltage is set by AMD to 1.35 V. Under idle lower voltage brings no improvements to power consumption but shaves off another 10 W in load state.

Temperatures

Sempron 140 runs very very cool and with some voltage tweaks passive cooling is possible.