No, the B450 chipset cannot fully utilize all 16 PCIE lanes of a Ryzen 5000G.
No, the B450 chipset cannot fully utilize all 16 PCIE lanes of a Ryzen 5000G.
Hello. In brief, I’m considering assembling a PC with a Ryzen 5 5600G. I plan to use the built-in GPU for light gaming and testing older graphics cards until I can acquire a discrete one later. From what I understand, previous APUs (before the 4000G line) typically run an 8 + 4 + 4 + 4 configuration, which allows PCIe 16 mode in the slot. The current Cezanne APUs operate at 16 + 4 + 4, using PCIe lanes directly connected to the CPU for discrete graphics. My goal is to see if a B450 motherboard, after BIOS updates, can still utilize those 16 lanes. I’m thinking this way because the new features won’t offer much advantage for my needs. For gaming, x8 mode seems fine, but I also want to handle heavy workloads that will use the GPU’s VRAM.
The paths from the CPU link straight to the slot, chipset is irrelevant.
Kilrah provided a partial response, but it doesn’t match your exact inquiry. You receive all 16 lanes, though the B450 only supports PCIe 3.0 even on CPU lanes. Splitting the x16 port will reduce performance slightly, since PCIe 4.0 isn’t required for most GPUs but usually needed when using more than PCIe 3.0 x8 lanes.
They simply aim to connect a GPU as usual and verified it would function at x16 without any changes.