OS X Rosetta Performance Benchmark

Geekpatrol benchmarks Rosetta performance, and concludes: "I'm impressed with Rosetta; Geekbench performance running under Rosetta is 40% to 80% of what it is running natively. Plus, running Geekbench under Rosetta is comparable to running Geekbench natively on a Power Mac G5 1.6GHz (our baseline system), at least in the single-threaded tests."

Check it