1080Ti on 18.04 LTS - should I upgrade GPU?

So I’ve got a 2018 Lambda Quad with 4x 1080Ti in it. Took quite a while to get everything sorted, and now it just works - mainly use PyTorch. DL / anomaly detection use cases.

I like the RTX 3090, but it seems like I might be buying trouble w.r.t. PyTorch. Plus I’m still figuring out if there’s not some sneaky hardware incompatibility in my relatively older machine.

Discussion of the pros / cons very much appreciated.