I got a Sapphire Pulse RX 5500 XT 4GB. It's one of the cheapest current generation (7nm Navi) cards and a review (below) said it was relatively quiet even under load, and the fans don't spin up at all under light usage. And like I said, all I need GPU for is to drive the display and basic stuff like video conferencing. I'm a programmer and don't do graphics or 3D work.
The AMD Radeon RX 5500 XT Review, Feat. Sapphire Pulse: Navi For 1080p
I put it in a Razer Core X Chroma. The Razer Core X and Chroma take the #1 and #2 spots on the eGPU.io enclosures list, looks nice, is easy to access the internals, provides 100W PD which the 16" MBP needs to avoid battery drain, etc. I got the Chroma version because I have a USB SSD for backups, wireless charging matt, and lightning/micro-USB cables to periodically connect various devices, and the Chroma has 4x USB ports. People say the ethernet doesn't work reliably and prefer the cheaper Razer Core X version, but I don't use the ethernet port.
The Razer Core X Chroma solved the thermal and resulting performance/heat/noise issues inside the MBP by dropping Radeon High Side down to 5W (same as if I was using the internal display only), or 0W if I disable the dGPU entirely.
The MBP noise level was mildly annoying at times, but I never really gave it any thought until I finally got fed up with the crippling 800MHz and 1000% kernel_task performance issues (on my 2019 15" MBP) which became more apparent with more/longer video conference meetings because of covid19. But if fan noise is one of your major gripes, the Razer Core X Chroma was still easily audible at all times because of the 60mm PSU fan. Probably equivalent to the MBP at 3000 RPM, but at a lower pitch. I swapped it out for a Noctua PSU fan that I think was equivalent to the MBP at 2500 RPM.
But my Razer Core X Chroma died after 4 months usage. Every time I turn it on, the PSU sparks and trips the house circuit breaker. So now I'm waiting for a new eGPU and this time I am going to try the new Mantiz MZ-03 Saturn Pro (v2).
According to this review (below), it appears to be equal or better than the Razer Core X Chroma in every way, for the price of the Razer Core X. It has 5 USB ports, ethernet, SD card reader, internal 2.5" mount points and SATA III interface. Similar "slide-out" mechanism to access the internals. And best of all, the PSU has a 120mm fan (up from 60mm) that should be less noisy out of the box, plus a fan-off mode for light usage.
Mantiz Saturn Pro Review - King of the Ring - eGPU.io
Priced to be the most affordable full-featured eGPU enclosure on the market, the Mantiz Saturn Pro delivers a knockout punch in performance and value. It showcases the best of the four-year evolution of Thunderbolt 3 eGPU technology. With a unique combination of good looks, unrivaled expansion...
egpu.io
Both of these eGPU options are BIG and HEAVY, though. 5.7KG for the Mantiz and 6.91KG for the Razer Core X Chroma. And both come with a relatively short 70cm TB3 cable. You might want to locate the box out of sight under the desk, with a 1M or 2M TB3 cable.
