Posted 18 May 2010 - 02:28 PM
Depends, as has been said, on your application and on the specific processors. Intel has dual core processors against which they apply what they call "hyper-threading" which is supposed to make the dual core sort of perform like a quad core. Have tried to find somewhere where the performance of these are compared against that of a quad core.
I have had the need recently to try to resolve this question for myself. My Dell computer with an AMD 2.3 GHz quad processor (as best I can remember the specs) ceased to work and Dell sent me as a replacement a machine with an Intel 3.2 GHz hyper-threaded, dual core (HTDC), claiming it is equivalent or better. Their representative said that the dual core should perform like a quad core because of the hyper threading. I was dubious and ran a series of self-developed benchmarks. These showed unequivocally that there was a significant "hit" in performance when multiple, cloned processes tried to run on the same core.
For most standard applications the 3.2 HTDC seems to be as fast or faster. However, when I try to run an "application" that consists of a large number of identical, but independent, processes, the HTDC seems to take a hit.
Without the speed difference and the hyper-threading, the dual core would certainly have performed worse than the dual core.
Hope this helps you consider the choices.