Thanks Dustin, this was a really interesting test. I had no clue that eSATA on a Macbook could be that much slower than on a Macpro while using the same drive. I would love to reach around 200 MB/s in my transfers with the Macbook pro. Of course it's tempting to go for a desktop computer when you see such a difference... but I love the portability of my rack. All I want from this system, is backup and preview of the footage, so to carry around a Mac pro for the sake of copying file seems a little overkill.
So if eSATA on laptop the bottle neck, then I guess Thunderbolt is the last alternative. The theoretical bit rates seems interesting, but how does that work on the field? Anyone using a laptop based solution with Thunderbolt, and reasonable RAIDs system, what do you reach?
An other thing is that MD5 requires some processing power, so that will be an other bottleneck with the laptop. Obviously we will to reach the performances of a desktop solution... But if I could double my transfer rate, I would then be comfortable with backing up 5K footage. Not always lagging behind.