Radeon Pro W6000X: Mac Pro gets AMD RDNA 2 with up to four GPUs

Apple upgrades the Mac Pro with new AMD Workstation graphics cards in the high-end category. The previous Radeon Pro Vega II and Radeon Pro Vega II Duo based on GCN 5 will be replaced by the Radeon Pro W6800X, Radeon Pro W6900X and Radeon Pro W6800X Duo with RDNA 2. Four GPUs provide a maximum of 60.4 TFLOPS (FP32).

The new Mac Pro in tower form, which has been available since the end of 2019, can now be ordered with new 7nm AMD RDNA 2 generation graphics cards. Apple draws a line under its brand-new GCN-5 graphics cards, the Radeon Pro Vega II and Radeon Pro Vega II Duo. With the Radeon Pro 580X as the base model, there is still an older GCN-4 graphics card with a Polaris GPU in the range. In addition, the Radeon Pro W5500X and Radeon Pro W5700X will continue to be available with RDNA.

Radeon Pro W6800X with 60 CUs for 3,220 EUR

Entry into the higher GPU category for the Mac Pro is now the new Radeon Pro W6800X as an MPX (Mac Pro Expansion Module) module for 3,220 euros. The graphics card offers 60 compute units, 3,840 stream processors, 32 GB GDDR6 on a 256-bit interface, 128 MB infinity cache and 16 TFLOPS FP32 performance with a 300W TGP.

Radeon Pro W6800X Duo with two RDNA-2 GPUs

The Radeon Pro W6800X Duo ranks even higher with two GPUs on a single board, connected to each other via Infinity Fabric Link at 84GB/s each direction, thus five times faster than via PCI Express. In an MPX unit for €5,750, AMD combines a total of 120 compute units, 7,680 stream processors, 64GB GDDR6 (all 32GB of 256-bit) and 256MB infinity cache, thus providing 30.2 TFLOPS FP32 performance with a 400W TGP.

Radeon Pro W6900X has 80 CU

The top model is the Radeon Pro W6900X for 6900 euros. The most powerful single GPU model offers 80 compute units, 5120 stream processors, 32 GB GDDR6 (256 bits), 128 MB infinity cache and an FP32 performance of 22.2 TFLOPS with a 300W TGP.

Maximum performance with four GPUs

Up to two MPX modules can be installed in Mac Pro, so two Radeon Pro W6800X Duo modules need to be combined for €11,500 for maximum performance. This combination of four graphics processing units (GPUs) provides 60.4 TFLOPS FP32 performance. For comparison: a previous Radeon Pro Vega II achieved 14.2 TFLOPS, a Radeon Pro Vega II Duo 28.4 TFLOPS and two Radeon Pro Vega II Duo in turn 56.8 TFLOPS – not much lower than now with RDNA 2.

Thunderbolt 3 and HDMI 2.0 as outputs

In parallel with the announcement of new graphics cards, Apple has an updated overview of Mac Pro technology for August 2021 (PDF), where, among other things, the new MPX modules are explained in detail again and the PCIe lanes assignments as well as Thunderbolt 3 and HDMI outputs are illustrated in several graphics.

Thunderbolt is handled separately via PCIe x4

For the Radeon Pro W6800X and Radeon Pro W6900X, their GPUs connect via PCIe 3.0 x16, two DisplayPort ports lead to the main logic board (MLB), and provide an Infinity Fabric Link for a second MPX unit, two individually via PCIe 3.0 x4 Titan Ridge controllers are connected to four Thunderbolt 3 ports and one HDMI controller to HDMI 2.0. The Radeon Pro W6800X Duo connects two GPUs to the board via Infinity Fabric Link and also provides this for a second MPX unit. Both GPUs are connected to the PCIe 3.0 x16 slot in the MLB via a PCIe switch to the two PCIe 3.0 x16 modules. Not only does the Radeon Pro W6800X Duo have a DisplayPort to MLB, but it also offers two Titan Ridge controllers connected separately via PCIe 3.0 x4 for four Thunderbolt 3 plus HDMI 2.0.

For new purchases and as a group

Apple sells the new MPX modules for new configurations of the Mac Pro as well as for existing systems as a stand-alone suite to modify them with more graphics performance. Apple has removed the Radeon Pro Vega II and Radeon Pro Vega II Duo MPX modules from their range for new configurations, but is still offering them as a stand-alone upgrade kit or as replacement parts.

New Intel processors should follow suit

No upgrade was done in the CPU area today. The Mac Pro is said to be about to switch from Intel Cascade Lake to Ice Lake-W. The number of physical cores or threads available will increase from 28/56 to 38/72. Additionally, the platform itself will bring higher IPC and raise the DDR4 RAM limit from 1.5TB to 4TB. According to Mark Gurman, an Apple insider, the CPU will be upgraded later this year Straight. The company will likely be the last to switch to Apple Silicon for the Mac Pro. Apple had already said when it announced its own processors that new Intel Macs would continue to arrive until the end of the switch by the end of 2022.