The U300 and U400 aren't your average mainstream rigs -- the 3.5-pound U300 measures .72 inches and the 4.4-pound IdeaPad 400 measures .88 inches in thickness. Both are available with Sandy Bridge processors, SSD and hard disk drive options, and up to 8GB of RAM. The U400, however, kicks it up a notch with a slot-loading optical drive and an optional AMD Radeon HD5470M GPU (with 1GB of VRAM).