Multi-GPU scaling: SLI and CrossFire
Destiny 2 supports both SLI and Crossfire which is a good thing at this day and age. In the graphs below, you can see the performance of the RX 580 and the GTX 1080 Ti each as a single GPU and with two of.
Starting at WQHD ultra is where using two GPUs comes in handy first. Single RX 580 manages only 54 fps at those settings while the Crossfire setup goes up to 75 fps. The scaling there is 39% getting up to 61% at 4K ultra. SLI scaling does even better reaching 69% at the highest settings.