Ubuntu 12.04 Desktops Impact Performance, Power Consumption
Next up is an older Intel Core Duo T2400 notebook with an ATI Radeon Mobility X1400 (R500 class) graphics processor with the open-source Radeon Gallium3D driver.
When idling, the GNOME Shell had about a one-Watt power savings over the other desktop environments. Interestingly, the KDE desktop was in poor shape on this ThinkPad notebook with it going through about two Watts more than the other desktops. KDE 4.8.2 was burning through about 19% more power than the GNOME Shell or 11% over the default Unity desktop.