tokynambu

tokynambu t1_j1tq28j wrote

No, it isn’t. That is why cpus need a lot of pipelining and speculative execution and caching and the like.

Mid 1980s, the choice when buying asynchronous RAM was, if memory serves, 70ns or 35ns latency. That when a fast processor was less than 20MHz (a Sun 3/160 was a 68020 clocked at 16.67MHz). So one cycle was about 60ns, and processors did not need to wait for RAM.

Today synchronous memory has a first word latency of the order of 10ns; that isn’t exactly the same as asynchronous latency but approximately comparable. But the processor is running at, say, 3GHz. So now, instead of people able to read RAM in a clock cycle or at most two, you need 30 cycles to access RAM. Clock is ~100x faster, RAM latency is only ~3x better. The RAM is much faster in bulk transfer (perhaps 50x or more) which helps for some operations, but a single random read is not helped.

Hence cache, pipelines, speculative execution, caches, more caches.

https://en.m.wikipedia.org/wiki/CAS_latency

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tokynambu t1_ixu9v5m wrote

I know that after holding a few trials after the war, almost everyone that was imprisoned for involvement in the Holocaust was freed, because the German population thought that it was not a crime. Consider, as a random example, Victor Capesius. Sentenced to nine years to make it look like Germany was tough on the Holocaust. Released after two and a half, because they didn’t really think it was a crime. Robert Mulka, Hoess’s deputy. Sentenced to 14 years (and not until 1964, because no could be bothered to prosecute him until then), released after four. And so on, and so on. Germany did not want to prosecute people who were the senior management of the Holocaust, and then when forced by international opinion to pretend to be outraged gave sentences that they never intended should be served. Klaus Dylewski, sentenced to five years (for “aiding and abetting murder on 32 separate occasions, 2 involving the murder of at least 750 people"), but only served three. Germany thought mass murder was not deserving of serious punishment.

Thank God Israel tried Eichmann rather than west Germany. A Bonn court would have given him a medal and a pension.

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tokynambu t1_ixtzx2b wrote

Japanese culture. Of course, now we are supposed to pretend it is entirely different. See also: Germany, where running death camps on an industrial scale is now completely dismissed as stuff other people did, nothing to do with us.

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tokynambu t1_iue8pg5 wrote

My car has them (Honda e).

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I was sceptical, but actually they have a load of benefits. You don't need to adjust them between drivers. The car is narrower. You can overlay distance cues. You can incorporate the images into an all-around "aerial" view. You can adjust the brightness. The passenger can see behind before opening the passenger door. In the case of the e, the world's least practical electric car, they also claim an aero benefit of a few percent, but I doubt that's worth the hassle.

None of these are game-changers, and none of them are of themselves reasons to do it. But the downsides --- they smear differently, and arguably worse, when it's dark and wet, they're a bit noisy in twilight --- are small compared to a lot of small benefits.

I'm much less convinced by central mirror as camera, because switching focus from infinity to a few inches from your eyes is hard, and harder the older you are. I have the central mirror as a mirror, rather than the camera. But door mirrors replaced by cameras? On balance, I'm impressed.

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