lets say i have a dual core having a speed of 2.7. Does the 2.7 stands for the sum of the speed of each core, or the speed of each individual core?
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I think this could be either on StackOverflow or on SuperUser, depending on whether you're looking at it from a programming or hardware aspect. – user541686 Aug 01 '11 at 04:10
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It means that each CPU core runs 2.7 billion cycles per second. This has a lot less meaning than it used to, as the amount of "work" that is completed each cycle varies quite a bit (due to considerations like caching, pipelining, hyperthreading, memory access times, and so on).
If you want to know how fast a processor is, it is much more advisable to look at benchmarks related to the kind of tasks you are trying to accomplish with it than to look at the clock speed. Consider: a dual-core 2.4 GHz Core i5 is much, much faster than a 2.4 GHz Pentium D (also dual-core).
Jeremy Roman
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yes, but that does not clarify how that 2.7 speed comes to be there. is it the sum of all the cores or the individual rating of each core. – cristopher cutas Aug 02 '11 at 01:03
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"It means that **each** CPU core runs 2.7 billion cycles per second." – Jeremy Roman Aug 02 '11 at 01:07
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aha!! found you! hehe i've asking around what that means. i have another question if you dont mind, seeing core i7 having 4 cores and 8 threads what does this mean? – cristopher cutas Aug 02 '11 at 01:15
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3The Core i7 microarchitecture has a feature called *hyperthreading* which I alluded to in my original answer. It allows a core to switch to another thread of execution while it is waiting for a low-level operation (like reading from memory) to complete. This appears to the operating system as eight cores (two for each physical core) so that the operating system knows to give the cores that much work to do. http://en.wikipedia.org/wiki/Hyper-threading – Jeremy Roman Aug 02 '11 at 01:17
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