This motherboard has the following PCI-E slots: 2 x PCIe 3.0/2.0 x16 (x16 or dual x8) 1 x PCIe 2.0 x16 (x4 mode, black) 4 x PCIe 2.0 x1.4 The PCIe 3.0 is populated by 2 R9 290 GPU's (CrossFire) So my only option is the PCIe 2.0 x16 (x4 mode, black) 2 are no issue, would this PCIe slot cripple NVMe speeds? M.2, formerly known as the Next Generation Form Factor (NGFF), is a specification for internally mounted computer expansion cards and associated connectors. M.2 replaces the mSATA standard, which uses the PCI Express Mini Card physical card layout and connectors.