NVIDIA has changed the way it approaches 3-way and 4-way SLI support for the GeForce GTX 1080 and GeForce GTX 1070. Now out of the box you can enable 2-way SLI by using either an SLI HB bridge (recommended for certain high resolutions), or even a classic 2-way bridge, 3-way and 4-way SLI will be restricted to a few non-gaming apps.
When the GeForce GTX 1080 and GTX 1070 were launched NVIDIA said it would officially not support 3-way and 4-way SLI for Pascal GPUs, however they setup a ‘SLI enthusiast key” webpage, from which enthusiasts can obtain a software key that unlocks 3-way and 4-way SLI support using classic bridges. So all NVIDIA would have to do was optimize a driver for 2-way SLI and then a gamer would get lucky if the game developer added in 3-way and 4-way SLI support. Well that is not the case anymore.
NVIDIA has reportedly removed the entire “software” key process of unlocking 3-way and 4-way SLI support. Now you should be able to enable SLI or 3-4 GPUs, but only a list of apps selected by NVIDIA will be able to take advantage of any 2+ GPU setup. These apps include popular benchmarking tools like Ungine Heaven, 3DMark FireStrike, and Catzilla. NVIDIA could possibly update this list with future driver updates.
I guess NVIDIA’s thinking behind this is to appease overclockers who only care able the score a benchmark spits out. This way they will not have to deal with complaints from gamers about choppy display output.
Pointless if you ask me. They just don’t want to fall behind AMD in benchmarks.