4 ms·
You also have penalties from context switches, although you can reduce their impact by performing them in a lazy fashion. AVX512 is even worse, of course.
by puzzle 8y ago
You also have penalties from context switches, although you can reduce their impact by performing them in a lazy fashion. AVX512 is even worse, of course.
- jeffreyrogers 8y agoYou need a context switch to use AVX?
- puzzle 8y agoNo, unless you have a special setup where one process on the whole machine can use AVX. That might make sense for special, controlled environments. What I meant is that there are more registers to shuffle around at context switch time, when multiple processes use the extensions.
- jeffreyrogers 8y agoAh got it, thanks.
- deleted 8y ago[deleted]
- yoklov 8y agoThat's true, these are always costly though.
- rphlx 8y agoTransferring SIMD/FPU regs to/from memory is actually fast - a modest fraction of the typical context switch cost - on modern x86_64 thanks to XSAVE.