Arnold 6.2.1 is out and it’s a performance release, bringing important optimizations on GPU, toon shading, and imagers:

• Inclusion of NVIDIA’s NanoVBD, resulting in up to 6x memory footprint reduction and 1.4x speedup for volumes on GPU
• Up to 4x speedup for Toon shading on many cores CPUs
• Up to 1.7x speedup for imagers on many cores CPUs
• Up to 1.2x speedup for SSS on GPU
• 33% memory reduction for polymeshes on GPU
• Faster interactive, progressive, and adaptive rendering
• USD improvements
• Many bug fixes

Release notes:

• Arnold Core
• Maya plugin
• 3ds Max plugin
• Cinema4D plugin
• Houdini plugin
• Katana plugin

https://www.arnoldrenderer.com/arnold/download/