Sounds about right. I did my testing on my 10850K before I started messing with overclocking properly (5.2ghz single, 5.1ghz dual, 5ghz quad, 4.8ghz all-core, tweaked numbers to 5.2ghz single/dual, 5.1ghz quad for the test. Now running 5.2ghz single -> quad, 5ghz all core)