you can use the 3tb in hfs+ , the jtag will read it ... you will need mac drive for windows or OSX 10+ to read it on the pc.
Hi, I have an RGH2.0 with 1TB internal =926.5GB available once formatted and 3 TB external =2794.2GB available once formatted, hope I helped
Really can't recall the program I used for the external 3TB as it was 2 years ago, for the 1 TB internal I just popped it in my rgh and formatted it through dashboard on latest kernal today (upgraded from a 250GB as I'm full up with DLC etc........... I'm not 100% but I think it was this http://fat32-format.en.softonic.com/
Best free program I have found is here: http://macrorit.com/free-ntfs-to-fat32-converter.html Haven't tested it on anything bigger than a 2tb yet.