THIS. I’m a software engineer who (among other things) helps Data Scientists optimize their Spark code to run better on clusters.

It ain’t happening, OP. Each computer would need to be running the full game as well as keeping everything perfectly synced between them. The performance would be straight-up worse than running on one PC.

Even without the complications of a network stack and the added latency involved, SLI is of dubious value for streaming your PC to another device because for each frame rendered on the secondary card you’d be bottlenecked by the latency of sending the frame back to the primary card before it can be encoded as part of the video stream.