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Bypassing the Branch Predictor

9 points| nicula | 11 months ago |nicula.xyz

2 comments

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fancyfredbot|11 months ago

That's clever!

It's weird to want your CPU to be slow on average and fast in the exceptional case but sometimes you want that. The CPU won't behave that way so you have to fake exceptional cases until they become the majority again.

I bet this is helpful for HFT.

nicula|11 months ago

Yeah it's quite interesting. I don't think I've seen this come up in anything besides that talk which is about the HFT space.

However, I did hear a few times about cases where you'd trade better average performance that comes with spikes (e.g. in terms of response time) in favor of worse average performance that has lower variance.