Depends on the workload. If the application is highly threaded, then it would perform better. If the application is not highly threaded (single-threaded or limited to two threads) then the dual-core would be better.
Thanks amnotanoobie and Thanks wisecracker, but as I asked, that I need to know "What is the difference between these two processors". The base question that help me to sort out the selection.
In simple words, I dont find any notes/article that explain them but found lot of people there looks confused and used the term interchangeablly or just dual for both. that makes more dig to both as both are labelled dual.
naturally the quad- term gives rosy picture that it is naturally somewhat looks faster then just dual, but need to know the some sort of difference, even with some techinically, to know their working so that i can choose depending upon the software I am using. My software is a customized software that takes too much load on processor just for launch like splash screen display. As lot of things are going on the background. Contains com, activeX, some threads (not heavily threaded- so amnotanoobie answer looks somewhat clear) but there are lot of others factors that need to know for decision.
Thanks again for both of you. I will be looking for more on this.