Yes, a lot of programs aren't mult-threaded, but don't be too disheartened, intel has turbo boost technology which boost the speed of the single core if the other cores aren't being used.
http://www.intel.com/content/www/us...ology/turbo-boost/turbo-boost-technology.html
http://www.intel.com/content/www/us...ology/turbo-boost/turbo-boost-technology.html