When first implemented, embree made waaay bigger difference in Corona than 30% - it is líke some crazy unicorn pony magic!
I also tested embree on an AMD rig, and it was not significantly slower. I suspect Corona is slower there because I only develop and optimize on Intel. Maybe sometimes in the future I will try to optimize also on AMD.
yes keymaster, that would be nice if corona is optimized for AMD
i believe that many of corona users are AMD users too. always wait for this development
The cold hard truth is that AMD are really quite far behind on the CPU performance curve at the moment. There isn't so much that can be done to optimize that away. Ondra's time is much better spent fixing bugs and improving functionality in Corona, rather than putzing around with low-level optimizations that are really the compiler's job. If you care that much about performance, just buy an Intel-based render slave. *shrug*
AMD were ahead back in the Pentium 4 days, but now they're behind. It happens. They might get ahead again, or someone else might get ahead; who knows. But right now, Intel are the CPU performance leaders. By a wide margin.