The GTX 1080 still supports 3-way and 4-way SLI over the classic bridges that come with motherboards, but you would have to obtain a special software key from NVIDIA and would rely on your game/benchmark developers to optimize their apps for 3-way/4-way SLI. NVIDIA's regular driver updates will likely only optimize for 2-way SLI. NVIDIA "Pascal" GPUs do support Microsoft DirectX 12's multi-display adapter (MDA) mode, but NVIDIA will not provide game-specific optimizations through driver updates for MDA. That would become the game developer's responsibility. The same applies to "explicit" LDA (linked display adapter).
LINKhttps://www.techpowerup.c...eForce_GTX_1080/3.html SO, "Enthusiast Key" website --- Is where?
Enthusiasts wanting to use 3-way or 4-way SLI would download an app from an upcoming "Enthusiast Key" website, run the app, and generate a software key signature for their hardware to unlock 3-way and 4-way SLI in NVIDIA's Control Panel.