This question is not a matter of how reasonable it is, but whether it's possible as a fun hypothetical so please bear with me. An increasingly smaller number of high end motherboards support 4-way SLI/Xfire which has always been the king of the hill since it was introduced with Windows Vista, exceptions like when people in AMD Xfired together 8 Fury X's on Linux notwithstanding. You could have dual SLI/Xfire, two cards for each of two monitors for a total of four. However, since Pascal and Vega Nvidia and AMD respectively have dropped official support for 3-way and 4-way SLI/Xfire even though you can still hack together 4 Titan Xps in SLI. It's conventional wisdom though that past two cards it doesn't scale well. You can have each monitor in a multi-monitor setup powered by a single card so could you have two cards in SLI/Xfire run each monitor in a three monitor setup for a total of six cards? This would be equivalent to having a dedicated dual card like the Radeon Pro Duo for each monitor. I know this is a dumb question, but I would appreciate any serious answers that explain why if this isn't possible e.g. not enough lanes on the motherboard or driver incompatibility.