In our testing, we used the Thunderbolt-equipped Promise . We also used a Promise SmartStor DS4600. (We don't have access to a non-Thunderbolt to an array that's similar to the R6.)

Our first few lab reports on Thunderbolt were done before Lion was released. Now that Lion has been released upon the Mac world, we ran tests to see if the operating system affects performance. We tested a Thunderbolt-equipped 17-inch MacBook Pro with a 256GB SSD with Snow Leopard and then with Lion.

Performance wasn't affected much by the new operating system. Each of our six tasks were a megabyte or two per second slower under Lion when testing eSATA speeds. Results were mixed on the Thunderbolt tests, though, with half of the tests (AJA System Test read, 2GB file read and write) speeding up under Lion and the half of the test slowing down a bit.

Overall, I'd say its a wash, with the average Thunderbolt file transfer speeds being less than one percent slower on Lion than on Snow Leopard, while AJA Read tests were 7 percent faster on Lion and AJA Write tests were 9 percent faster on Snow Leopard.