Set-up a Multi GPU server from Scratch | by Shivaraj karki | Medium
Always wanted to build a dual GPU system. Unfortunately it's kind of a dead tech now so I did it pretty cheap. Don't know the performance due to my PSU deciding not
Choosing a Gaming CPU: Single + Multi-GPU at 1440p, April 2013
Someone just used an AMD and Nvidia GPU at the same time | Digital Trends
History of ATI/AMD dual-GPU cards | MyGaming
Dual GPU Gaming Gives Up the Ghost as Nvidia Ends SLI Support | Extremetech