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Can someone clear up the terms Core Duo CPU, Quad Core, Dual CPU, etc.?

In a processor, what is the core? I hear the terms i3, Core 2 Duo, and Dual Core, what do they mean, especially in reference to cores?

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migrated from stackoverflow.com Apr 23 '11 at 18:30

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marked as duplicate by Sathya Apr 23 '11 at 20:25

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3 Answers 3

According to Wikipedia:

The core is the part of the processor that actually performs the reading and executing of instructions.

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If you quote something from somewhere, or get information from somewhere else, always link to your source, both now and in the future. Cheers! –  studiohack Apr 23 '11 at 18:54
    
@studiohack I come from StackOverflow and I edited my answer but the changes were not applied during the transfer (stackoverflow --> superuser). Sorry ;-) –  Sandro Munda Apr 23 '11 at 18:56
    
no worries @SandroMunda :) welcome to SU! –  studiohack Apr 23 '11 at 18:58

In a multi-core processor it is like having more than one processor. Dual core processor has two processors.

From Wikipedia: "A multi-core processor is a single component with two or more independent actual processors (called "cores")"

(emphasis added by me)

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It's not true ! Dual core processor has ONE processor with TWO cores. –  Sandro Munda Apr 23 '11 at 18:57
    
I suspect we are arguing semantics. I added a quote from Wikipedia to my answer. –  uSlackr Apr 25 '11 at 17:01
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You definitely aren't arguing semantics: "dual processor" implys it is actually a second processor with it's own bus and it doesn't share a cache at any level... Having it's own bus is a BIG deal it give the second processor direct access to component on the motherboard. In a "dual core" setup both cores share the bus and the level 2 cache and are they are also on the same die... –  Kyle Apr 25 '11 at 17:21

You actually have two separate questions there; unfortunately, neither one permits a succinct answer.

"Core", when capitalized, is probably an Intel product name / trademark. For example, Core i3, Core i5, Core 2 Duo, etc. Unfortunately, there's a lot of confusion in Intel's product naming; Intel has names related to the manufacturing process used to build a chip, and these all might result in the same consumer name. Take a look at http://en.wikipedia.org/wiki/Intel_Core_i5 - you'll see that Core i5's can be Lynnfields, Clarkdales, Arrandales, or Sandy Bridges.

"core," in the general sense, refers to something akin to the processing unit of a CPU. An old Pentium, for example, would have some of the chip for processing and some of it for fast on-chip memory. A multicore processor would take several of the processing units - the cores - on the same piece of silicon, but might share the memory (the caches) between the cores. To your operating system, each core appears to be a separate CPU.

This is a very high-level answer, you can easily find books written about this.

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