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How many PCIe lanes do I need?

Quartz

Quartz

Quartz

Soldato
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Or, Rocket Lake vs Ryzen vs Ice Lake Xeon vs Threadripper.

Consumer Ryzen and Rocket Lake motherboards come with 24 PCIe lanes: 16 for the GPU, 4 for the NVME, and 4 for everything else, multiplexed out to 16 or so. Threadripper and Xeon (Ice lake) boards have 64 or more natively.

But if you add in anything extra either it cuts into the 16 GPU lanes, thus reducing the GPU's performance (marfginally right now, but what of the future?), or uses some of the multiplexed 4 lanes, meaning it doesn't operate at full speed. Consider a USB video capture to a multiplexed NVME drive. So how many PCIe lanes should a consumer CPU supply? I think an extra 8 for one or two add-in cards and an extra 4 for a second NVME drive seems about right, for 36 total. How about you?
 
I'm looking at the Intel page for the Ice Lake Xeons and I'm not seeing any single-CPU chips. Nor is Google turning up any workstation motherboards. I hope they'll release workstation Xeons sometime soon.
 
Journey said:
especially as running even an RTX 3090 at 8x 4.0 PCI-E has no impact at all for people playing games,
Click to expand...

The problem comes when you have direct GPU-NVME access as in the PS5. Which is coming soon. Suddenly those 8 lanes get reduced to 4. 16 lanes down to 12 isn't an issue; 8 lanes down to 4? I think that that's going to be an issue, even for PCIe v4. Roll on PCIe v5!
 
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