I have a 4 bay Drobo connected via FW800 to a Late 2009 Mac Mini.
When playing my movies that I ripped using Ripit they tend to briefly pause during playback. Usually several times and usually towards the end of the movie. Surely I have enough bandwidth or maybe I don’t. Or maybe the Minis not up to it.
You can check if the playback is pegging the Mini by running Activity Monitor while the playback is in progress.
However, it’s been my experience that the Mini (even 1st Gen) can handle 1080p playback with no problems.
Is the Drobo the only device connected via the FW port? I originally had issues with my Drobo when it was connected to my i7 iMac and my ‘old’ 1TB FW drive was daisy chained through it. I removed the 1TB drive and the Drobo worked perfectly.
BTW- my Drobo is now about 88% full and I get 14MB/sec writes and 35MB/sec reads via FW800.