MB: ROG Crosshair Hero VII WIFI.
CPU: Ryzen 2700X.
GPU: 4 of R9 Fury X, First 2 connected in top MB slots at PCIe 3.0x8, third connected in PCIe2.0x4 slot 3. Fourth connected via M.2 PCIe4.0x4 slot using ADT-Link interface.
RAM: 64GB Corsair Vengeance RGB Pro
SSHD: Seagate 2TB
OS Windows 10 19.03 with latest updates and checks out fine.
1. Poor DX11 Crossfire scaling and performance with Adrenalin 2019 Drivers, specifically 19.10.1,2 and 19.11.1. on 3DMark Fire Strike DX11 tests.
2. Very unstable and frequently crash, especially in TriFire/QuadFire.
3. Works well on same machine if I DDU and clean install Crimson ReLive 16.12.2. I get much better results.
I have submitted an AMD Reporting form using 19.11.1 GUI report here:
I understand that DX11 Crossfire Support is dropped for new cards like Radeon VII and RX5700/XT, but I think it should still work on older cards properly.
Right now using 3 or 4 R9 Fury X beats a pair of RX Vega 64 Liquids, and you can only Crossfire 2 RX Vega 64's.
Evidence here using 19.11.1 driver and same GPU driver and CPU settings settings on same PC : Result
Quad R9 Fury X produces lower performance on 19.11.1 than Dual R9 Fury X in DX11 CrossFire.
This is definitely not the case on older drivers such as 16.12.2 where running with Triple or Quad R9 Fury X outperforms Dual R9 Fury X every time.