BoostClock
Latest Blender update boosts AMD dGPUs OpenCL performance in Cycles

With the release of Blender 2.79 the popular and free DCC suite features much faster AMD OpenCL path tracing code and feature parity with NVIDIA CUDA. Since Blender 2.75 a new approach (split kernels, OpenCL pipes) is implemented in Cycles to remedy compilation and performance issues regarding AMD cards. AMD continued work with the implementation means that Radeon dGPUs' performance is on par with similarly positioned (price & performance) GeForce cards in the latest iteration of Blender. It's important to highlight that only GCN1.1 and newer AMD dGPUs are supported.

Test methodology

To test Blender we picked 3 scenes from the Blender Institute-prepared benchmark pack. The cards are divided into 2 groups based on their performance. The final score covers only pure path tracing time - no OpenCL kernel compilation, scene loading, CPU-side BVH construction, final composition. Blender was launched headless (no GUI) with a python script responsible to get everything sorted and start the rendering process.

Conclusion

  • the RX 580 is faster than the GTX 1060 (2.7% bmw27, 22.4% classrom, 7.3% pavillon)
  • the RX 560 falls short in the fight with the GTX 1050 - no repeat of the strong showing of the big Polaris chip
  • one would have expected stronger performance from the R9 380X - numerous workstation cards and the 2014 / 2015 edition of the iMac Retina 5Ks wield Tonga-variants
  • relative performance differs by scene - the complex indoor environment of 'classroom' favours AMD cards; NVIDIA cards show better results with the studio shot of 'bmw27'; the GTX 970 (1664 CUDA cores) can beat the GTX 1060 (1280 CUDA cores) in 'classroom' & 'pavillon' despite its lower FP32 performance

All in all, it's great that now Radeon users can fully utilize their dGPUs in Blender. Hopefully, these sort of improvements can find their ways into software in a more timely manner - Hawaii-based dGPUs made their debut in late 2013.

Hardware setup

PSU: Cooler Master V1000

MOTHERBOARD: Gigabyte GA-AB350-Gaming3

CPU: AMD Ryzen 5 1600

GPU DRIVERS: NV 385.41 / Crimson ReLive 17.9.1 (17.30.1081)

RAM: HyperX Savage 16GB (2X8GB) DDR4 2400MHz

STORAGE: Samsung m.2 SATA 500GB SSD 850 EVO

COOLER: AMD Wraith Spire Cooler

OS: Windows 10 Home

AMD GPUs: Sapphire NITRO R9 380X 4G D5 / Sapphire NITRO R9 390X 8G D5 / Sapphire R9 Nano 4G HBM / Sapphire PULSE RX 560 4G D5 / Sapphire NITRO+ RX 480 8G D5 OC / Sapphire NITRO+ RX 580 8G D5 LE

NV GPUs: MSI GTX 960 GAMING 4G / MSI GTX 970 GAMING 4G / MSI GTX 980 GAMING 4G / MSI GTX 1050 GAMING X 2G / MSI GTX 1050Ti GAMING X 4G / MSI GTX 1060 GAMING X 6G / Gigabyte AORUS GTX 1060 Xtreme Edition 6G