PCIE Lanes?
PCIE Lanes?
Hello, I'm trying to grasp PCie lanes but haven't found clear guidance online. I think my CPU has 20 lanes and the motherboard (TUF B660 PLUS) offers several slots: two PCIe x16, one Gen 5, one Gen 3, three NVMe (all 4th gen), two x4, one x2, plus two PCIe Gen 3 x1 slots on the MOBO. My main question is how many devices can I install? Can I use all three NVMe drives in the Gen 3 slot and also connect a GPU or other expansion ports? Or should I limit myself to some? How do I determine the total lanes my components require? Any advice would be greatly appreciated. ❤
The PCIe configuration of the 12400F leans more toward a 20+8 setup. Four lanes are reserved for an M.2 device, sixteen lanes serve general purposes (typically assigned to the GPU), and eight lanes connect to the chipset—though on the B660 only four of those chipset lanes are utilized. The chipset then converts those four lanes into fourteen PCIe lanes that distribute bandwidth to the CPU. How the motherboard allocates these thirty-four total lanes depends largely on the vendor, with some boards offering shared SATA ports or bandwidth-sharing connectors; details can be found in the manual. Based on a quick review, the board doesn’t inherently share bandwidth, suggesting you can fill every slot for optimal performance. However, it’s not unusual to encounter situations where using two PCIe slots reduces lanes or causes an M.2 port to fail, or a PCIe slot to malfunction. Just remember, while this board avoids those issues, other boards may handle them differently.