The evidence seems pretty hard to argue, but Samsung wants to try anyway. Multiple sources have found that Samsung (as well as most other Android manufacturers) artificially boost CPU frequencies when the system detects a benchmarking test running. Samsung is denying that its devices are trying to cheat the tests, and is actually putting the blame on the tests themselves...
Source: http://www.phonearena.com/news/Samsung-denies-cheating-on-benchmark-tests_id47949
Source: http://www.phonearena.com/news/Samsung-denies-cheating-on-benchmark-tests_id47949