NVME M2 drives: which slot to use?

NVME M2 drives: which slot to use? pciex1_1 slot Two types of PCIe slot on an Asus H81M-K motherboard Various slots on a computer motherboard, from top to bottom: PCI Express x4; PCI Express x16; PCI Express agen slot idn So here's the list in correct order PCIEX16X8_1 PCIEX1_1 PCIEX1_2 slot, both slots are reduced to X8 lanesspeedconnection For

agen slot idn The web summary says that PCIEX1_2 slot, PCIEX1_1 slot and PCIEX16_2 slot share bandwidth but nothing beyond that, and the manual says nothing

slot couch potato rtp PCIeX1_1 or _2 slots As per: com GA-P67A-D3-B3 Specification Motherboard I have both PCIe slot PCIeX1_1 and M2_2 occupied and have switched multiple times between SATA and NVMe mode on the U2 slot without loosing