RTX4000 Hardware Platform


The RTX4000 card suggests that it should be used in a PCIe3.0 x16 slot. The size of the card means the slot size should be x16 but can anyone suggest or do you have experience with what happens if the slot size is x16 and the slot runs at x8 speed?

Depending on slot configuration in motherboards PCIe slot speed rates can often move down when there are multiple PCIe slots populated so I am trying to understand if having this in a x16 physical size slot but x8 speed slot is likely to impact performance of the card.

Ps. Understood it would remove any doubt to have it in a x16 speed slot but just trying understand possibilities here.

Any feedback welcome.

I am assuming that by “RTX4000 card” you actually mean a Quadro RTX 4000.

Possible performance impact depends entirely on your use case. From what I have seen over the years, CUDA-accelerated applications rarely use more than 40% of PCIe gen3 x16 bandwidth of about 12 GB/sec in each direction. So the likely outcome of using a PCIe gen3 x8 connection instead of a x16 connection is an application-level performance degradation in the low single digit percent.