msi b550 unfy

Hello, MSI B550 UNIFY Board has total four M2 slots. 1st is directly coupled with CPU, 2nd and 3rd M2 slots actually share PCI-E 4.0 x 16 bandwidth. If I put SSD in any of these M2 slots, PCI-E slot brought down to x8 mode. This is fine as long as there is graphics card installed in PCI-E x 16...