AMD's Kabini-based APUs cannot be evaluated based on performance alone. This 15 W processor is meant to go into mobile devices driven by batteries, and lower power use translates to more compact and lighter platforms.
Let's measure consumption in three disciplines: gaming, Web browsing, and HD video playback. The following tests are run by removing each notebook's batteries, plugging them into the wall, and logging power use. In order to factor out each system's LCD, we turn them off and in favor of an external monitor.
Although the A4-5000-based notebook is soundly bested in our F1 2012 benchmark, it also uses a lot less power than the Core i3- and especially the Pentium-based laptop.
The 14 W delta between A4 and Core i3 is particularly notable since the processors driving those platforms have TDPs only 2 W apart.
Web browsing doesn't apply as much of a graphics load, so we're seeing more impact from the x86 cores. The field narrows substantially, but A4-5000 remains the most power-friendly option.
All three of these platforms feature fixed-function logic able to accelerate H.264 playback in hardware. So, the workload isn't much more demanding than simply browsing the Web.
Each solution appears equally adept at offloading the decode process, so we again see the A4-5000 in first place, with Intel's Core i3 just 2 W higher.