Verified answer

In a controlled environment yes. But think of it this way... 1 person doing math problems with a nice calculator or 2 people doing math with regular calculators. One's going to heat up and get tired quicker. I'd go with the dual core. It can handle multitasking easier.

not necessarily. having a dual core CPU does not mean you can add the frequency of both and you have a total. like a dual 1 GHz CPU would equal a 2 GHz single core CPU.

in some instances it may be faster since it can do 2 things at once. and in some instances it may not be where a singlethreaded application will not be able to fully utilize dual cores.

however a dual core 1.0 GHz is kind of hard to find nowadays. any i3, i5 or i7 CPUs will not let you down. anything else may not be worth it depending on what you want to do with the system.