Looking for help from members who know the deal when it comes to TM storage. I got my new iMac and now I want to update from crappy USB 2 speeds for my Time machine back up. I'd like to use the Thunderbolt ports and keep the USB 3 ports from for other things. I'm looking at this external... LaCie 2TB Little Big Disk Thunderbolt Hard Drive (5400 rpm) It's 20,000 yen here in Japan (about $ 220 USD) but because it's got two 1TB drives inside, will that cause trouble for Time Machine backups bigger than 1TB? Obviously I'd set up the raid for type 0, but after that it is a bit murky. Thanks. SM.