As an electrical engineer, I currently have a Precision M90, one of the predecessors to the M6400. Even with Core 2 T7200, 2GB RAM and a Quadro FX2500M, the battery lasts at least an hour and a half when only surfing on the internet or using Office products. It is truly a workstation, though. It will run Pro/E without any problems and no noticeable difference from the Precision 690 workstation tower that I had before. The real b!tch is actually carrying the thing around. It's heavy!