Question about ASUS GeForce GTX 1070 STRIX O8G GAMING

Which mainboard do you have? Except in some cases with the Socket 2011-v3 mainboards, the cards in SLI are necessarily reduced to 8 lanes per card, since only 28 CPU lanes are available in total. I don't notice any losses, they talk about 2 -3 % less performance with 8 lanes instead of 16 lanes operation, you don't notice that (at 60 fps it's 1 fps less...) But then you have 2 cards. I also play with 2 Strix 1070 OC on a WQHD screen (2560x1440). For example, with Mirrors Edge Catalyst it is still over 100fps with the "Hyper" setting. Witcher 3 etc. are well over 100 at the highest settings.
However, I recommend an HB-SLI bridge (I installed the EVGA HB bridge) and a G-Sync monitor. The micro-stutters are almost imperceptible.
When used as a single x8 card, the frame loss is also minimal. I also had to do this once because of CPU cooler space problems, but I had the same gaming enjoyment...