Originally posted by: dguy6789
X2 easily.
Anyone can run sandra and see that their cpu scores higher or whatever, but there will be no tangible difference in real world use in one task between a 2Ghz X2 and a 2.6Ghz 64.
However, ponder these scenarios:
You are burning a cd or dvd and want to play game at the same time. It would be near impossible on a single core cpu, and if you do manage to get it to work, one of the two programs would run extremely slow. With a dual core, both programs will run at full speed completely independant of one another, as well as if you were running two separate programs on two separate machines.
Suppose you were transferring large files over a network. If you wanted to play a game at the same time, the transfer would be bogged and slow down like crazy on a single core. On a dual core, whether you play the game or not, the transfer will still be going at normal speed.
Your antivirus has not been run in a few weeks. It keeps popping up and wanting you to run a complete scan. With a single core, you can only do very light tasks while scanning antivirus. With a dual core, you can go ahead and do the most intensive tasks your computer can do while scanning for viruses without issue.
Then there is the benefit of multithreaded software, which is becomming more and more common as time goes by. Those pieces of software have a wide range of possible performance gains, with games like Quake 4 showing near 100% performance gains in cpu bound scenarios.
The bottom line: With a dual core, you do not have to wait on your pc to finish some long boring task just to open up a game(or another demanding application), while with a single core, you have to wait, and wait, and wait for whatever you are doing to finish before you run another demanding application.