PCIe v3 slot with PCIe v4 GPU

My motherboard has PCIe v3 x16 slots, and I'm looking to get a new GPU card. I know they're backward compatible, but the most recent nVidia RTX cards that are meant for PCIe v3 are the 20 series cards. But I'm wondering if a 30 series card, even though the performance will be degraded, might still have an advantage over a 20 series card just due to the speed of the onboard processing? I'm considering getting an RTX 3080 ti, but if it's only going to perform as well as a 20 series card in my computer, then I'll just get a 20 series card. Does anyone have any advice or know where there might be posted a comparison of 20 series vs 30 series running on a board with PCIe v3? Thanks!

There is a PCIe 4.0 vs. PCIe 3.0 GPU Benchmark:
PCIe 4.0 vs. PCIe 3.0 GPU Benchmark | TechSpot

This is perfect! Thank you, itsme1! :)

Nothing to worry about you are not going to gimp the card on gen 3 and off paper its going to not be noticeable if in some scenarios it does, overall though not an issue.

Frametime is going to be measured in the MS which 1000ms is 1 seconds of delay when you are asking something like is gen 3 going to gimp the card then all you need to know is that your resolution will play the key role at determine how much this is a factor to you..
Realistically though its going to be down in the very minuscule ranges if anything and it will be so minute its not even worth bothering asking that sort of question in fact this sort of stuff is just stuck on the hype train where its about squeezing bees dcks for profit margin.

Also on paper and off paper are two very different things and people get caught up in the hype train. Who cares plug the card into gen 3 and enjoy it all this other stuff is influencer hypetrain.

Thank you, Malneb, I won't give it another thought!