Question Performance difference if a video card is running in a PCIe 3.0 x8 slot and the same card in a PCIe 4.0 x4 slot (x16 physical slot).

[rvidd]

If two similar (high end) PCIe 3.0 video cards, one running in a PCIe 3.0 x8 slot and the other running in a PCIe 4.0 x4 slot, will there be any performance difference between them? Theoretically both slots will give the same speed. But will the PCIe 3.0 card utilize the full potential of PCIe 4.0 lane speeds?

 

[jay32267]

There is little difference between 4 lanes and 16 lanes (I assume he's running 3.0).
See link.

View: https://www.youtube.com/watch?v=eglDVG84zIQ

I would expect the same or maybe even less difference with PCIe 4.0 and 4 lanes.

 

[rvidd]

There is little difference between 4 lanes and 16 lanes (I assume he's running 3.0).
See link.

View: https://www.youtube.com/watch?v=eglDVG84zIQ

I would expect the same or maybe even less difference with PCIe 4.0 and 4 lanes.

But my question is, Gen 3 x8 slot vs Gen 4 x4 slot.

 

[jay32267]

But my question is, Gen 3 x8 slot vs Gen 4 x4 slot.

That's all I could find in my limited search.
Although I think we can conclude there isn't much difference.

 

[SkyNetRising]

But my question is, Gen 3 x8 slot vs Gen 4 x4 slot.

Gen 3 graphics card in Gen 4 slot will still operate in Gen 3 mode.
So - it makes no difference, if you're putting it into Gen 3 or Gen 4 slot.