4 ms·
Intel do that with a lot of old instructions I.e. MMX and SSE instructions are really really fast on AMD but horrible on Intel. I guess this is to force people
by andy_ppp 6y ago
Intel do that with a lot of old instructions I.e. MMX and SSE instructions are really really fast on AMD but horrible on Intel. I guess this is to force people to upgrade to the latest and greatest AVX whatever.
- yvdriess 6y agoCitation needed? I've never encountered that, and used plenty of those. The main reason old instruction become slow is that the hardware implementation is replaced by a microcoded version.
- dogma1138 6y agoMMX these days costs extra instructions on both AMD and Intel CPUs. This has been the case since SSE and SSE2 were introduced and later AVX extensions. There quite possibly been a point in time where certain MMX instructions run faster on some AMD CPUs and required less uOps to achieve. https://agner.org/optimize/ https://agner.org/optimize/ This is a pretty good source for uOps and instruction cycles.