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Why does he see no point in multithreading?
by p1esk 10y ago
Why does he see no point in multithreading?
- gpderetta 10y agohyperthreading != multithreading. He is saying, correctly, that the core doesn't have the resources to handle more than one thread per clock cycle (like for example server class CPUs can); but KNL has hyperthreading for the opposite reason: a single thread can't normally feed the core two new instructions every clock cycle, so you need more threads to keep the core busy on those clock cycles it would be otherwise stalled. Although he dismisses it, he actually mentions the reason: 'perhaps [it is useful] for code that is limited by memory access, branch mispredictions, or long dependency chains': especially the first and the last are going to be common on code running on KNL.