The ASUS Prime Z370-A supports multiple PCIe lanes.
The ASUS Prime Z370-A supports multiple PCIe lanes.
Hi, I’m looking into the PCIe lane configuration on this motherboard. The specifications list all PCIe slots as PCIe3.0/2.0. This seems unclear to me. Is the generation tied to the CPU? With an i3-8100 that supports up to 16 PCIe3.0 lanes, which lanes connect to the CPU and which go to the chipset? Are the chipset connections also PCIe3.0 or limited to 2.0? I’m focusing on the basics here—no need for the AIC details. It appears the three x16 slots can be arranged in certain setups: x16-empty-x4 or x8-x8-x4. Does that sound correct? It makes sense that the CPU could handle 16 lanes, so the layout should match that capability. Regarding the four PCIe x1 ports—do they all use PCIe3.0 and can they operate together without conflict? Thanks in advance for your assistance. Best, -a-
The initial two PCI-E X16 ports get PCI-E lanes from the CPU, providing sixteen lanes overall. The motherboard supports PCI-E X8 in each of these slots when both cards are installed. The remaining PCI-E lanes come from the chipset. The bottom PCI-E X16 port contains just four lanes, resulting in a total of eight lanes available. The chipset connects to the CPU with a configuration similar to a PCI-E 3.0 x4 setup, so all chipset-related connections are compressed into that equivalent format for the CPU (when data needs to reach it). Additionally, the board offers bifurcation support via the Asus Hyper card option, which divides the first PCI-E X16 slot into three PCI-E X4 connections leading to the M.2 connectors on the card. However, only three devices can be used at once, meaning if you install an Asus Hyper card for three M.2 SSDs in the first slot, the second PCI-E lane becomes unusable.
Thanks a lot everyone! @TrigrH and @mariushm, you're doing great.
I believe the important point is that the hyper M2 support which identifies 2 or 3 M2 disks instead of just 1 in PCIe X16 won’t work unless your GPU has only 8 PCI lanes. By the way, this setting doesn’t change your standard M2 slots, just the disks placed in the first two PCIe X16 ports. You can also utilize the third PCIe X16 port for x4 independently.