Battery performance on larger, powerful laptops is rarely a highlight of the product however other than gaming with the two GTX 280 cards enabled the M17x gives us some very acceptable use without mains power. We are able to watch just over two hours of high definition content at 1080p and surf/write and listen to music for nearly three.
Before taking the temperature of the system the M17x was left idle at the desktop for 30minutes. For the load tests we performed sustained rendering on Cinebench for the CPU tests and played Lost Planet at 1280x720 and 1920x1200 for the GPU tests.
The results above are very impressive for a system with so many high specification components inside it. For general use there are were no issues with sitting it on our lap, even at full load the design of the M17x kept the base of the system cool and had the air exhausting out of the rear. As long as our legs were positioned to allow air into the bottom vents the system was perfectly useable when balanced on our thighs.