alt Hacker NewsWhat is the "nasty surprise" of Zen 4 AVX512? Sure, it's not quite the twice as fast you might initially assume, but (unlike Intel's downclocking) it's still a strict upgrade over AVX2, is it not?
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fooker • yesterday at 11:53 PM
> it's still a strict upgrade over AVX2
If you benchmark it, it will be slower about half the time.
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It's splitting a 512 instruction into 2 256 instructions internally. That's the main nasty surpise.
I suppose it saves on the decoding portion a little but it's ultimately no more effective than just issuing the 2 256 instructions yourself.