As of Arnold 4.2.16.2, the requirement is now “just” SSE4.1.

This blog post is for Google search to find; I’ve already blogged about the SSE4.1 requirement elsewhere.

If your processor does not support SSE4.1, the Arnold won’t run on your computer. MtoA will either fail to load, or you’ll get a crash whenever you try to render.

To check whether an older machine supports SSE4.1, here’s a few suggestions:

• Google your processor and “SSE”
  cpu-world is pretty reliable, but I have seen one or two cases where the info was wrong, and SSE4.1 wasn’t really supported by a processor.
• Windows: Download and run coreinfo -f
• OSX: Run sysctl -a | grep machdep.cpu.features
• Linux: Check /proc/cpuinfo

A note about coreinfo:

• If you see an asterisk (*), then SSE4.1 is supported.

  SSE4.1          *       Supports Streaming SIMD Extensions 4.1

• If you see a dash (-), then SSE4.1 is not supported.

  SSE4.1          -       Supports Streaming SIMD Extensions 4.1