Core i5 2400/2500 supporting only 16 pcie lanes?

[yhwhshua.lamoore]

Im building a budget build that is an optiplex 790 dt, with a gtx 1050 ti low profile, 16 gb off ddr3 ram and a core i5 2400/2500 of course. I would like to also add a pice x4 quad bus usb card, so it can run vr, but when i did the math and the research, i see that my processor can't both gpu and the usb card, since they equal a total of 20 pcie lanes, in which leaving me 4 lanes short, is this correct? or will both gpu and usb card work? or will it force my gpu to an x4 bandwidth?

 

[InvalidError]

Intel's CPUs have 16 PCIe lanes from the CPU for the GPU(s) and another dozen or so PCIe lanes from the chipset for other stuff. If you use GPU PCIe lanes for a USB board, then the GPU lane gets downgraded to x8 to let the other CPU-hosted PCIe slot use the other x8.

 

[yhwhshua.lamoore]

Well the usb card is going into the pcie x16 wired as x4 slot, will it downgrade the gpu lane to x4?

 

[InvalidError]

If the slot is wired using CPU PCIe lanes, then the main PCIe slot will get downgraded to x8. If it uses chipset PCIe lanes, then the main GPU slot remains x16.