Comment by bigyabai

2 days ago

It's workload-dependent. On-paper, ARM is more power-efficient at idle and simple ops, but slows down dramatically when trying to translate/compose SIMD instructions.

You seem to have conflated SIMD and emulation in the context of performance. ARM has it's own SIMD instructions and doesn't take a performance hit when executing those. Translating x86 SIMD to ARM has an overhead that causes a performance hit, which is due to emulation.

  • Both incur a performance hit. ARM NEON isn't fully analogous to modern AVX or SSE, so even a 1:1 native port will compile down to more bytecode than x86. This issue is definitely exacerbated when translating, but inherent to any comparison of the two.