4 PCIe Slot Features of the ASRock B550 Phantom Gaming 4

Primary x16 slot runs at PCIe 4.0 This slot delivers full Gen 4 bandwidth for your graphics card, which is the main reason to buy this board.

Second x16 slot runs at PCIe 3.0 x4 That slot connects through the chipset, not the CPU, so it tops out at Gen 3 speeds with four lanes.

Two PCIe 3.0 x1 slots are available These handle smaller add-on cards like Wi-Fi adapters or sound cards without wasting lanes.

The lane split is practical Gen 4 bandwidth goes to your GPU where it matters most, while Gen 3 handles everything else without compromise.