I'm thinking of using a SeaGate 250/500 GB portable hard drive for Time Machine back ups. Roughly how long can I use this? I'm just doing some photoshop stuff and papers. Nothing hard core. A bit of gaming. Possibly some Fusion and Boot Camp Stuff. Will any of that interfere with Time Machine? I know FileVault has problems. Is the rest ok? Please hurry cause I want to get them tonight before they sell out.