Lane mix-ups in PCIe connections PCIe pathways can become mixed up, leading to performance issues.
Lane mix-ups in PCIe connections PCIe pathways can become mixed up, leading to performance issues.
You have an i7-8700K with full support for 16 PCIe lanes. Your setup includes a GTX 1080 in the first PCIe x16 slot and a Tesla K80 in the second. You're using two M.2 NVMe SSDs and two SATA3 HDDs. The BIOS indicates the GTX is using all 16 lanes, which seems contradictory since you only have one PCIe x16 slot. The K80 shows only x4 lanes, while your motherboard has two x16 slots. It appears the NVMe drives are likely managed via DMA on the CPU, and the M.2 SSDs are probably accessing the bus through the PCIe lanes. The screenshots suggest some confusion about lane allocation. Are the 1080 and K80 sharing lanes equally or differently?
Thank you for the image. It matched what I anticipated, yet my BIOS screenshots are displaying an unexpected result. I’m curious whether my Tesla K80 is recognized as a GPU or if it’s being treated as another type of device. Since it’s showing my 1080 running at x16 lanes, that seems inconsistent.
He shared the image he uploaded to clarify the situation. Every PCI-e port except the first uses lanes from the chipset. That means everything is working fine.
I didn’t catch his edit. Thanks to @DejaVoodoo for the clarification. What bothers me is the official spec sheet for the Z370-A-Pro—it mentions only the physical width of the slot, not the number of lanes it supports. This means my initial assumption was incorrect. The chipset appears to manage the Tesla K80 instead of the CPU, which makes a lot of sense. On another point, the SATA1 port is functioning properly since I’m using an M.2 NVMe SSD in the dedicated slot, not a M.2 SATA drive. No problems there.