Minimum number of PCIE lanes to effectively use a 1080 ti?

I’m trying to build a PC that can hopefully utilize 4 high end gpus, in the range of a gtx 1080 or equivalent. My current build will have a i7 8700k cpu which has 16 pcie lanes. However this will limit my gpus to 4 lanes each. Will this have a significant effect on my learning tasks? I’m also considering below to maybe pcie 1x. Are any of these practical for deep learning? Thanks

yeah, 8700k is very nice CPU and cost effective, but not many lanes. Keep in mind that if you use NVME drives it will likely eat another 4x PCI lanes per drive.
1080Ti for DL works same on 16x and 8x PCI lanes as I can tell.