To add the 2nd GPU showed up to be rather simple:
- Open Folding@home Client Advanced Control.
- Open the Configure window.
- Pick the Slots tab.
- Click Add.
- Click the GPU radio buttom. Go with the default values, typically -1.
- OK - Save
In both Web Control and Advanced Control the 2nd GPU is now present.
Each folding slot works on its own package in its own Work Queue, so you can see a mixture of different activities.
When all CPUs and GPUs are working your power consumption wil be high for a significant time. You should keep an eye on hardware errors and keep the room well ventilated.
Now all there is left is to hope this can contribute to a solution to the current Covid-19 pandemic.