There's still nothing in the notebook world that can touch the largest desktop drives, which now offer up to a portly 2TB, but the latest capacity milestone notwithstanding, mobile hard drives have begun closing the gap. Today we take a look at Seagate's newest Momentus model, the 7200.4 500GB hard drive. Representing the largest capacity yet offered in a notebook drive, Seagate also says its latest Momentus is also the best performing. That's a big claim, and not only will we throw the hammer down on the Momentus, but we'll test two of them in a RAID 0 array, giving us 1TB of total storage spinning at 7200RPM.