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> you can't have parallelism with one CPU What about multithreading? If a single core switches between tasks I can see that not being true parallelism, but wha
by _greim_ 12y ago
> you can't have parallelism with one CPU
What about multithreading? If a single core switches between tasks I can see that not being true parallelism, but what about multi core?
- curryhoward 12y agoYou're technically right (multi-core CPUs can do true parallelism), but you were downvoted probably because your point was obvious (to the people who downvoted you). A multi-core CPU is basically multiple CPUs. The details (multicores share the same die, use the same caches, etc.) are mostly irrelevant here.
- ww520 12y agoMultithreading on a single CPU doesn't have parallelism. You are just switching between tasks very fast serially. A multi-core CPU for all intents and purposes has multiple CPU's. For the discussion on concurrency and parallelism, the distinction is on one execution unit vs multiple execution units.
- lloeki 12y ago> Multithreading on a single CPU doesn't have parallelism. You are just switching between tasks very fast serially. Nitpick: SMT[0] (implemented as Hyper-Threading by Intel) is in fact parallelism for threads on a single CPU. [0]: http://en.wikipedia.org/wiki/Simultaneous_multithreading http://en.wikipedia.org/wiki/Simultaneous_multithreading