A multi-core processor works by spreading the CPU load evenly through-out the cores, depending on if the application is threaded
So a game for example, Lets say Call of Duty Mw 3? The game is multi-threaded for 4 cores, This allows the workload of the game to be spread out evenly on the cores, so say 15% load on each core.
The Idead of multi-core processors is the share the working load, by doing this it increases the rate of spead tasks can be done, as you can have multiple things open, all sharing the CPU workload from diferent cores.
It all depends on if the software is multi-threaded
Also dont assume that a quad core at 2.4ghz is 9.6 ghz in total...Its just straight 2.4ghz. it shares it over each core, so for examples 2 cores, running an application at 2.4ghz, they dont stack to run at 4.8ghz, but just straight 2.4ghz