Hi,
I'm using 2x RX5700 for rendering in Blender (cycles opencl), but I can't get the second GPU to work at PCIe 4.0. GPU-Z says it's operating @x8 1.1 even while rendering and it's noticeably slower than the first card.
In idle, GPU-Z says both cards are running at x8 1.1. Once I start the render GPU 1 switches to 4.0 but GPU 2 stays at 1.1.
System specs:
- Ryzen 7 5800X
- MSI MEG X570 Unify
- 2x Asus RX5700 installed in slot PCI_E1 & PCI_E3 which support PCIe 4.0 x8/x8
- Windows 10 20H2
What I've tried:
- High performance power plan - no difference
- Link State Power Management off + restart - no difference
- Enable mGPU - no difference (as expected, but worth the try)
- Plug second monitor into second card - no difference
- Set PCIe gen 4.0 in BIOS instead of 'Auto' - no difference, still downclocks to 1.1
