It appears that the new GTX 1080 will only support 2-way SLI, thanks to the new SLI HB technology, which means that there won't be any way to connect more than two GTX 1080 graphics cards.
The SLI HB (High-Bandwidth) technology introduced with Pascal-based GTX 1080 and GTX 1070 graphics cards should double the available transfer bandwidth compared to Nvidia Maxwell-based graphics cards, at least on paper. While we still did not see any real performance numbers, Nvidia promises "silky-smooth gamepley" and describes the new SLI HB as the best way to experience surround gaming.
According to a report from Videocardz.com, who spotted
a confirmation coming from an EVGA employee, the GTX 1080 and GTX 1070 will only support 2-way SLI and currently you can choose three different SLI HB bridges, depending on the slot configuration. All have four SLI connectors and will only work with two graphics cards.
Old, non-HB SLI, bridges should be still compatible with GTX 1080 and GTX 1070 graphics cards so those can be used in case you want to pair more than two GTX 1080/1070 graphics cards.
We should hear more about these SLI HB bridges as soon as reviews go live on May 17th.
Source:
Videocardz.com.