I have two GTX 1080s and two 1440p 144 Hz monitors in a system that I use for both gaming and professional engineering software. I sometimes enable SLI or multi-GPU hardware acceleration depending on the application. Is it better to connect both monitors to the primary GPU, or should I connect one monitor to each card? I'm mainly wondering whether either setup affects performance, SLI behavior, or workstation applications.
2 Answers
For most modern games, two GPUs provide little or no benefit because multi-GPU support is uncommon or has been dropped. When support does exist, scaling is usually well below double the performance. Some professional applications can still benefit, but that depends entirely on the software. Keeping both monitors on the primary card is the simpler and more flexible choice, especially if the second GPU is disabled for a particular workload.
The performance difference will probably be very small, so there isn’t a universal advantage to splitting the monitors between the cards. I’d connect both displays to the primary GPU. That way, if you disable or remove the second card, both monitors still work, and you avoid adding another variable to your setup. Since you can test both arrangements yourself, benchmark the games and engineering applications you actually use and keep whichever configuration behaves better.
That makes sense. The second GTX 1080 was free, so I added it mostly to experiment with SLI and to take advantage of the engineering software that can use multiple GPUs. I’ll keep both monitors connected to the primary card and test the applications from there.