They are expensive, they are rare, but they are fast! I'm talking about accessories compatible with Thunderbolt ports, which have already gone through a benchmark gives Macworld, but have now been further tested by Robin Harris of ZDNet, and the result is that there is nothing better, if pure speed is what you seek.
The speed test above, Blackmagic Design, evaluated the performance of PROMISE Pegasus Thunderbolt RAID 5 and came out with a result of 348.3MB / s for writing and 332.2MB / s for reading. In a video editing context, this is more than enough to transmit 1080p content with maximum depth and color space in a single workstation. It is only a warning that such a performance can depend on a lot of RAM and that the configuration of the RAID can be quite complex, in case you want to change what comes from the factory.
Harris took advantage and compared the performance of a Mac Pro in Xbench quad-core 2.66GHz with 300GB 10k Velociraptor drive, ATI Radeon 5770 GPU with 1GB and 12GB of RAM with that of a top of the line iMac with 3.4GHz Core i7 processor, 1TB HDD, 1GB AMD Radeon HD 6970M GPU. While the tower scored 185.51, the all-in-one came out with a 269.65 gain of 45%, and still with a nice 27 ? IPS display as a bonus.
(via 9 to 5 Mac)