So I am thinking about building a media server so that I can stream HD videos (1080p) to my iMac, MBP, HDTV and other devices. I have been toying with the idea of getting a Mac mini and swapping the HD for a 3TB drive to put all my movies, TV shows etc (mostly mkv files). I am thinking for the TV I could connect a Roku with a Plex app. The key for me is if the Mac mini is fast enough to transcode the HD video. If so could it do multiple sources simultaneously? Has anyone tried this? What about an older Mac mini (to save money) how do they fair? I would love to hear about what others have done. Any ideas about this?