@d-healey Well the sets are not correct, SSE 4.2 is NOT the highest or newest that HISE uses. Most likely AVX and AVX2 aswell. Or indeed I would have to dig out that old spiked-on AMD cpu in my intel machine.
Architecture = "native" is the issue. It over-rides any setting you make in hise. It uses your build-cpu´s sets available to do the best enhancements available. And whoever said IPP is the only thing in need of higher sets hasnt read the amount of issues on this topic over at the juce forums.
Setting Architecture to x64 in the .jucer project is the ONLY thing I was able to start my instrument build with. That flattens it to x86_64, which is basic original specs of the first 64-bit cpus, so no SSE3 or above, most likely.