Sorry guys, I meant the WD Black NVMe (https://www.wdc.com/en-um/products/internal-ssd/wd-black-nvme-ssd.html)
On WD Site it says, it uses PCIe Gen3 8 Gb/s, up to 4 lanes
So, my question is, can I add WD Black M.2 on the Asus Z97AR mobo without getting the GPU down to X8 from 16X at present...