Power, Efficiency, And Battery Life
Given its Radeon HD 5770-based architecture, we are surprised to find the Mobility Radeon HD 5870 with higher idle power than the GeForce GTX 285M. Because it’s part of global wattage measurements, higher GPU idle power also affects the CPU Full Load test reading. The GeForce GTX 285M has higher GPU load wattage, while far higher power draw for the desktop platform shows why these types of parts are not used in notebooks.
Battery Eater Pro runs a small 3D demo continuously. Given the Mobility Radeon HD 5870’s lower load power, we are surprised to see that the unit provides less battery run time. A relatively short battery life from a desktop replacement makes it worth considering the spare battery option if you spend a lot of time away from wall sockets.
The average performance chart above gives us the “work” side of the efficiency equation.
AVADirect’s GeForce GTX 285M build edges out its Mobility Radeon HD 5870 version. The desktop PC’s superior graphics performance softens the fact that it isn't as efficient as the AVADirect notebooks.