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what's the difference between a P-core and an E-core? special machinery for caching, branch prediction and speculative execution? i still have the antiquated
by a-dub 3y ago
what's the difference between a P-core and an E-core? special machinery for caching, branch prediction and speculative execution?
i still have the antiquated view that performance and efficiency are essentially the same metric and these are the only kinds of ideas i can come up with that would separate them..
- MBCook 3y agoE-cores are physically smaller and have fewer execution units and what they do have are more likely to be shared, I think. So they simply can’t process as much clock for clock.
- monocasa 3y agoThey also have smaller resources like reorder buffers so they can't speculatively keep nearly as much in progress work around, leading to more stalls.
- zamadatix 3y agoSpeculative architecture is one thing but plain ol' superscalar architecture can make things run faster by simply executing more instructions per cycle, given you dedicated the die space to additional execution units to do more things at the same time.
- ip26 3y agoA semi truck is a very efficient way to move a lot of packages across the country very quickly. It is a terribly inefficient way to move a single envelope. Deeper speculation, larger out of order window, more accurate branch prediction, larger caches, more execution pipes, larger register files…