motherboards with 3 m.2 slots

Ideally, M.2 slots use 4 PCIe lanes, which means for the NVMe SSD to perform at its peak, it needs 4 PCIe lanes. But on some motherboards, the M.2 slot may be connected to only 2 PCIe lanes.

But X570 Taichi supports up to 3 M.2 slots, while B550 Taichi has only 2 M.2 slots. These M.2 slots are all equipped with aluminum heatsinks for best heat dissipation when operating.

PCI Slots, Riser options with up to 8 PCIe Gen 3 slots, maximum of 4 x 16 slots, 4 PCI-E 3.0 x16 2 PCI-E 3.0 x8* ; M.2 Interface, NONE, 1 PCI-E 3.0 x4 NVMe M.2 ...