4 ms·
What is a vector unit was is simd etc can be confusing but at least some wikipedians are sure the early Crays had true vector processing (which may not be paral
by college_physics 4y ago
What is a vector unit was is simd etc can be confusing but at least some wikipedians are sure the early Crays had true vector processing (which may not be parallel processing according to your definition)
https://en.m.wikipedia.org/wiki/Vector_processor https://en.m.wikipedia.org/wiki/Vector_processor
- hedgehog 4y agoYes, in the Cray design a vector instruction processes one item per clock so total latency increases with number of elements. Only parallel in the sense of pipelining being a form of parallelism. Something like an AVX-equipped Intel CPU processes all elements in parallel to deliver a result in an essentially constant number of cycles. Edit: There's a period write-up of the general Cray 1 design here: https://inst.eecs.berkeley.edu/~n252/sp07/Papers/Cray.pdf https://inst.eecs.berkeley.edu/~n252/sp07/Papers/Cray.pdf