Hi all,
We are considering using e-gpu enclosures with the new Nvidia RTX 3090. This would allow for a more modular approach to upgrading our existing workstations.
What would the performance difference rendering on VRAY GPU using a Thunderbolt 3 external GPU enclosure vs an internal GPU?
Is it even worth it?
Thanks
I’ve done this some times ago with a Notebook abd a 2080. I don’t know if it would be faster or anithing since i can’t put the card inside the notebook. The notebook have 2x1080 and the 2080 from egpu is faster and less Hot. I think the only real issue could be the time to send all data to egpu by thunderbolt. But i don’t see a very different loading time between the internal 1080 and the egpu 2080.
From my experience, Thunderbolt EGPU with a 2080 is working very fine. i don’t know with a 3090 
One especially made for rtx 390.
https://www.gigabyte.com/fr/Graphics-Card/GV-N3090IXEB-24GD/sp#sp
But thunderbolt is only 22 GB vs 128 Gb bandwidth PCIe, so I wonder if it’s really a wise choice!
The bandwidth will eventually cripple the interactivity depending on what do you use it for. F.e. in theory it won’t matter if you are doing production rendering (default RPP/RBS or higher) but it will for real-time calculations like Vantage.
An year ago I’ve made some tests with a RTX 8000 and for Vantage (then Lavina) I got around 10% performance loss vs plugged in the PCIe. I guess it also depends on the mainboard and the processor.
Thanks, 10% drop that’s very surprising, I was expecting at least 50% due to the bandwidth difference.
We just need to wait to get a decent price on such rtx 3090.
Thank you all for the feedback.