None. The m.2 shares bandwidth with the PCIe x1_1/2 slots.
Thanks for answering. I have 4 regular SATA 6.0 and 2 PCI Express SATA ports (backward compatible to 6.0) on my z97-AR for a total of 6 ports. So you're saying that if I install an SSD into the M.2 slot I can can still use all 6 SATA ports for other devices? I thought for some reason that using the M.2 interface disables one or more other SATA ports.