4 ms·
For >= 256 bit operations you need to decide to commit to them or not. If you go all-in on them and use them well, you will get the same work in less time and
by corysama 6y ago
For >= 256 bit operations you need to decide to commit to them or not. If you go all-in on them and use them well, you will get the same work in less time and less joules than without them. If they won't help, don't use them. But, popping in and using them for tiny bits would be the slow and hot worst of both worlds.
- foota 6y agoDoesn't this hurt other users/applications on adjacent hyperthreads or cores? Or is it just HT?
- chrchang523 6y agoNit: most 256-bit AVX2 integer instructions (exception: multiply) do not trigger downclocking.
- quotemstr 6y agoIs there a central list of these safe instructions?
- chrchang523 6y agoI currently follow the guidance in this Stack Overflow answer by Travis Downs: https://stackoverflow.com/a/56861355/3245034 https://stackoverflow.com/a/56861355/3245034 . I'm not aware of a more central source of truth.
- MaxBarraclough 6y agoThis turned up over here too. [0] Apparently Intel's CPUs are more inclined to downclock than AMD's. [0] https://news.ycombinator.com/item?id=23810654 https://news.ycombinator.com/item?id=23810654