I can't speak for core 2 duo specifically, but I do tons of browsing on ThinkPad t420s (per parallel thread) which has Core i5-2540M. Depending on specific core 2 duo this shows as about 20 percent faster per interwebs - could be wrong. I find for browsing memory is king. Note I don't have any noscript or js killer, just pure browsers on windows 10.