4090 on 13th Gen intel i7 shared with M.2 NVMe SSD (PCIe 5.0)

[sweet locust]

Looking at getting an RTX 4090 with an i7-13700k whilst also having a PCIe 5 SSD.

From the specs it seems the 13700k has x16 PCIe lanes at 5.0 and x4 PCIe lanes at 4.0. Ideally, I would put the 4090 on all 16 5.0 lanes but then I would only have PCIe v4.0 remaining for the SSD (I am aware the 4090 uses PCIe 4.0). It seems my only option is to share the 16 5.0 PCIe lanes to take advantage of the PCIe 5.0 SSD but then I am worried I will be losing performance on the GPU and/or SSD; I have heard that sharing PCIe lanes with different components can degrade performance. Would this then mean only x12 PCIe lanes are available for the GPU? Would this in fact then degrade to x8 PCIe lanes for the GPU if it can only use a lane count which is a power of 2?

This article https://www.techpowerup.com/review/nvidia-geforce-rtx-4090-pci-express-scaling/single-page.html#introduction talks a bit about the problem and also does a system test with the 4090. It mentions how AMD CPUs like Ryzen 4000 do not suffer from this issue of running out of PCIe 5.0 lanes, as all 20 lanes make use of PCIe 5.0.

From their 4K benchmark (as I am using a 4K monitor), it seems to only have lost very little performance.

Is this an issue I should be concerned with? Should I consider looking at AMD CPUs to try and squeeze the most out of the 4090? It is annoying the 13th Gen Intel CPUs don't have 16 PCIe 4.0 lanes and 4 PCIe 5.0 lanes instead.

[glacial ocean]

x8 actually since x12 isn't a valid configuration

however

PCIe 5 SSDs are hot and toasty and provide practically zero advantage over PCIe 4 for heavy storage workloads, and PCIe for most purposes

[sweet locust]

So for the most part you wouldn't really notice load time differences?

If I were to use a PCIe 4 SSD rather than 5

[glacial ocean]

For the matter, PCIe 3, as long as they're high end enough to saturate that

If you do end up having a PCIe 5 SSD, there are two options you can choose (or three, rather)

1. Buy a motherboard that has the CPU M.2 be PCIe 4, making this irrelevant (caps to PCIe 4 speeds for the SSD)
2. Use a chipset M.2 (same)
3. Use the PCIe 5 M.2 slot anyway (this cuts the GPU bandwidth to half the max, though as of this writing you won't notice anyway)

Though, as PCIe 5 SSDs are too cutting edge and hence rather immature, I'd probably stop at a high end PCIe 4