Fortnite Trailer - Multi GPU Usage?

The Fortnite Trailer white paper describes, in detail, the real-time pipeline used to create the trailer. It is a very well done paper. At the end of the paper, it describes the PC configuration used in the production of the trailer as follows:

PC Configuration:
• PC - i7 (7th Gen processor or higher)
• 64 GB RAM
• SSD Hard Drive
• 1080 GTX / 1080 Ti / P6000

I gather from this that 3 GPUs were used. However, they don’t really address how they were used. Does anyone know how the multiple GPU configuration was used? Were they designating different GPUs for different tasks? Were they using multiple GPUs to render? If so, how did they include multiple GPUs for rendering?

Any insight would be appreciated.

Most likely they used multiple systems to render different parts of it rather than trying to use multiple GPU’s at the same time. DirectX 12 is technically able to use multiple GPU’s but that feature hasn’t been supported by UE4.