How many PCIe lanes does a PCIe Network Card use?

[Tech Wizard]

I have a 4930K (40 lanes), and I'm using a GTX 1070 + 1x PCIe Network Card. That's 20 lanes on those two combined yeah?

Also, my father is using a 4770 (16 lanes) with a GTX 1060, and he wants to buy a PCIe Netword Card instead of USB. What's gonna happen to his lanes? 4x to network card, 8x to GPU and 4x available, or have I missunderstood PCIe lanes? Thanks in advance.

[Mira Yurizaki]

It depends on where you plug it in. If you plug in the card in a slot not meant for a graphics card, then it will not use the CPU's PCIe lanes. But otherwise yes, if the network card uses up the PCIe lanes on the CPU, that's how it'll distribute it.

[Rubin Chen]

Not 100% sure about 4th gen but z370 motherboards have basically another 4 pcie lanes for nvme and stuff not sure if they get used good question!

[Tech Wizard]

5 minutes ago, M.Yurizaki said:

It depends on where you plug it in. If you plug in the card in a slot not meant for a graphics card, then it will not use the CPU's PCIe lanes. But otherwise yes, if the network card uses up the PCIe lanes on the CPU, that's how it'll distribute it.

4 minutes ago, Rubin Chen said:

Not 100% sure about 4th gen but z370 motherboards have basically another 4 pcie lanes for nvme and stuff not sure if they get used good question!

 

Here's my father's motherboard (Intel DH87MC), marked with the PCIe slot that he wants to use his network card for with a red circle. Will this steal lanes from GPU or not?

[Mira Yurizaki]

1 minute ago, Tech Wizard said:

Here's my father's motherboard (Intel DH87MC), marked with the PCIe slot that he wants to use his network card for with a red circle. Will this steal lanes from GPU or not?

No. It's safe to assume x1 slots will route to the chipset.

 

However I would like to assuage your worry about stealing lanes from the GPU, because even a GTX 1080 doesn't see major performance hits until it gets down to PCIe 1.1 x8.

Edited December 11, 2017 by M.Yurizaki

[SupaKomputa]

16 lanes (the blue) provided by the processor connects directly.

the others are provided by the chipset. so you'll get enough it not more.

Most of the GPU still use x8 bandwidth even if plugged in x16.