Solved! pcie 4.0 x8 lanes with RTX 3080

[pallab]

Since nvidia demonstrated the RTX 3080 gpus with PCIE 3.0 x16 lanes on a intel system, I wonder if pcie 4.0 x8 lanes are enough for this gpu. Theoretically the bandwidths for 4.0x8 and 3.0x16 are equivalent.

Because the gpu has support for pcie 4.0,
which is more preferable 4.0 x8 lanes or 3.0 x16 lanes?
( Even if the bandwidths are same, electrically x8 and x16 slots pose a difference. I want to know what is the effective difference in performance)

 

[Cableman]

Even 3.0x8 makes no difference:

NVIDIA GeForce RTX 3080 PCI-Express Scaling

NVIDIA Ampere finally brings PCI-Express 4.0 support to the high-end graphics market. The new interface promises twice the bandwidth of PCI-Express 3.0. We've setup an AMD Ryzen 3900XT system to test how various PCIe generations and lane widths affect gaming performance.

www.techpowerup.com

 

[pallab]

Even 3.0x8 makes no difference:

NVIDIA GeForce RTX 3080 PCI-Express Scaling

NVIDIA Ampere finally brings PCI-Express 4.0 support to the high-end graphics market. The new interface promises twice the bandwidth of PCI-Express 3.0. We've setup an AMD Ryzen 3900XT system to test how various PCIe generations and lane widths affect gaming performance.

www.techpowerup.com

This article doesn't cover 4.0x8 lanes. Moreover, I am also considering creative workloads.
I was wondering if the 8 lanes (with 4.0) pose some restriction compared to 16 lanes with 3.0.

 

[Cableman]

This article doesn't cover 4.0x8 lanes. Moreover, I am also considering creative workloads.
I was wondering if the 8 lanes (with 4.0) pose some restriction compared to 16 lanes with 4.0.

Did you even read the article? Do you know the bandwidth limitations of the different PCIe versions? Of course the article covers 4.0x8, and if an RTX3080 does not even saturate 3.0x8, how can it saturate 4.0x8/3.0x16? Your use case makes no difference.

 

[pallab]

Did you even read the article? Do you know the bandwidth limitations of the different PCIe versions? Of course the article covers 4.0x8, and if an RTX3080 does not even saturate 3.0x8, how can it saturate 4.0x8/3.0x16? Your use case makes no difference.

Your concept of bandwidth saturation is wrong.

 

[Cableman]

Your concept of bandwidth saturation is wrong.

Sure.

 

[lightmanek]

This article doesn't cover 4.0x8 lanes. Moreover, I am also considering creative workloads.
I was wondering if the 8 lanes (with 4.0) pose some restriction compared to 16 lanes with 3.0.

Yes, creative use will be able to saturate PCIe 4.0 x16 connection, just needs large enough dataset to spill to RAM or compute algorithm frequently requesting data over this connection. Large rendering projects/ video filters in 8k and more can and will utilise PCIe 4.0 bandwidth, just not yet the current games.
Coming to your main question, if anything, PCIe 4.0 x8 should be a bit faster than full 3.0 x16 due to lower latencies. I myself would be interested in some tests showcasing both gaming at 4k or 8k in Doom Eternal and creative workloads with large datasets. I expect very minimal differences, probably even less than 1%, so in grand scheme of things, both PCIe configurations should be equal.