A multi-core chip can execute multiple instructions at the same time.
Dual cores have two cores, and quad cores have four. All the cores are on the same chip though. So, they share the same memory, and data path to the motherboard.
So, a quad core chip may be able to execute the instructions four times faster, but that doesn’t mean it can receive instructions from ram four times faster.
Also, the faster a CPU is, the hotter it gets. Just because the CPU is a quad core doesn't mean it was set to run at the same gigahertz.
Consider a manufacturer that wants to sell a 4 gigahertz chip, but the core keeps melting. One could sell a Quad core chip with each core set to 1 or 2 gigahertz and get increased performance, but still be running each core much slower. Therefore the chip no longer melts.
Software has to be rewritten to take full advantage of multi-core processors. The operating system might provide a small automatic increase in speed, but you won’t see a 4X increase in performance simply by switching to a quad core.
Even if the software is rewritten it might not be 2X, or 4X faster because now the program may have additional instructions added for the sake of figuring out which core is going to access each part of the program.
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Dual cores have two cores, and quad cores have four. All the cores are on the same chip though. So, they share the same memory, and data path to the motherboard.
So, a quad core chip may be able to execute the instructions four times faster, but that doesn’t mean it can receive instructions from ram four times faster.
Also, the faster a CPU is, the hotter it gets. Just because the CPU is a quad core doesn't mean it was set to run at the same gigahertz.
Consider a manufacturer that wants to sell a 4 gigahertz chip, but the core keeps melting. One could sell a Quad core chip with each core set to 1 or 2 gigahertz and get increased performance, but still be running each core much slower. Therefore the chip no longer melts.
Software has to be rewritten to take full advantage of multi-core processors. The operating system might provide a small automatic increase in speed, but you won’t see a 4X increase in performance simply by switching to a quad core.
Even if the software is rewritten it might not be 2X, or 4X faster because now the program may have additional instructions added for the sake of figuring out which core is going to access each part of the program.
-http://answers.yahoo.com/question/index?qid=20071104225157AAHxzkS