Another NVIDIA GTX 480 quad SLI test surfaces - SlashGear
Nvidia drops most support for three and four-way SLI - ExtremeTech
When Quad SLI isnt enough | NeoGAF
NVIDIA's Quad-SLI Graphics Makes a Comeback - NVIDIA's 790i Arrives: SLI Rides Again
CyberPower Inc. - What's better than quad-SLI NVIDIA GeForce GTX Titans? How about quad-SLI Superclocked GTX Titans? How does your machine compare? Tell us about it! | Facebook
Quad SLI problem with sli bridge | [H]ard|Forum
4K Showdown - ASUS GTX 980 4GB in Single, SLI, 3-Way SLI and 4-Way SLI | TweakTown