Testing conducted by Apple in November 2019 using preproduction 2.5GHz 28-core Intel Xeon W-based Mac Pro systems with 384GB of RAM and dual AMD Radeon Pro Vega II graphics with Infinity Fabric Link and 32GB of HBM2 each and shipping 2.3GHz 18-core Intel Xeon W-based 27-inch iMac Pro systems with 256GB of RAM and Radeon Pro Vega 64X graphics with 16GB of HBM2, as well as shipping 2.7GHz 12-core Intel Xeon E5-based Mac Pro systems with 64GB of RAM and dual AMD FirePro D700 graphics with 6GB of VRAM each.
