It seems everyone now is following MSI incorporating reinforced PCIE-slots and here with the "graphique" application to the MoBo (tho here done poorly). Even if you don't use 3 or 4 GFX cards, the extra slot spacing was oft chased by enthusiasts to provide wider card spacing and better cooling. But it has now been shown that with current MoBos, that having the switch negatively impacts 2 x SLI / CF performance.
SLI performance with the 3rd or 4th card never brought significant gamoins as scaling was very poor compared to adding the second card. And now SLI isn't officially supported with 3 or 4 cards, nor can it be said that it is much supported at all as the days of 70+ average scaling and 95 to over 100% in the real hardware demanding gains are gone. Now we see 18% at 1080p, 30% at 1440p ... only at 4k do we get to anything cost effective.
Whether this exists because nVidia just didn't want 1080 sales to be cannibalized by 2 x 1070 sales as it has been since the 5xx series or because AMD had nothing to compete w/ the two cards that support SLI is unknown. But if my budget is going to be taped by a MoBo in this price category, I'm going to be forced to look elsewhere because of the inclusion of cheaper on board componentry and having a fan header that doesn't support both PWM and DCV control is just silly. This was to be more price competitive ? Increase margins ? or to allow inclusion of RGB ... no thanks to all.