Just a word of caution - the 1080/1080ti are currently not supported by MacOS. You can find many posts written by frustrated Hackintosh users around the world stating that they only got a black screen after upgrading their GPUs to the 10xx series. I tried installing MacOS on my PC (6700K, 64GB DDR4 RAM, GTX 1080, both PCI and SATA SSD) with no success. After turning on the integrated graphics and disconnecting the 1080 the MacOS worked. I removed it though because I primarily use the computer for 3D rendering software, which only makes sense when I can use the discrete card to boost the performance.