Even though this podcast went for three hours, there are many things I wish I'd explained better. So I will attempt a better explanation of my kind-of-throwaway Amdahl's Law comment, as the situation is pretty interesting:https://twitter.com/oxidecomputer/status/1221804818030706688 …
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to do this. But, back in the early 2000s, the situation was different. We still knew how to make single processors faster by making their pipelines deeper and making them more out-of-order and speculative. But that was starting to take a lot of transistors, so there was this
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idea, hey, instead of using all those transistors to do this out-of-order stuff, we could just have (in the case of PS3) a bunch of blazing-fast SPU coprocessors that are very simple and linear, or (in the case of X360) three in-order main processors instead.
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Unlike today, where we don't have a tradeoff to make ... we just know how to add more cores, we can't make one core faster ... back in that time a tradeoff was made: we can have more potential compute power, *as long as we make the slow part of our system slower*.
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Because in-order cores are slower than out-of-order cores, potentially *much* slower in some cases. But people decided to do that. And this runs afoul of Amdahl's Law ... with it you should see clearly that making B twice as slow as it could be (or whatever) is going to be
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much worse than making A faster, in almost all cases, unless B is a tiny part of your program, which it never is, especially for games. Both consoles made anti-Amdahl tradeoffs; I think both would have been much better with just a single out-of-order CPU at the same price point.
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Kraj razgovora
Novi razgovor -
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What significant changes in the world we'd see if 32x faster single-core monsters were possible?
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