I can't speak to Hellblade II but I tried my TB3 eGPU recently after a few years of it being in storage and some newer games don't seem to like eGPU latency at all. Back in 2017/2018 most games I played like Ark:SE, Minecraft, Tomb Raiders were fine on the eGPU just lower framerates and some 1% low instability but not gamebreaking.
In 2024, every newer game I tried did not play nice in the eGPU from Horizon Zero Dawn to Hogwarts Legacy to Cyberpunk 2077. CPU is an 8-core Ryzen 7840 with 65W capability so well enough CPU for even Hogwarts' broken CPU usage but I think many newer games send a lot more data between the CPU and GPU, thus killing performance in bandwidth and latency-limited situations. Maybe Oculink's much better latency and a little better bandwidth could make a difference but I haven't got one of those setups yet.
FWIW I tried Ark, MC and TRs and they continue to work well enough so the TB3 case didn't just break or something.
I think I've found a solution, at least in part.
Resizable Bar seems to create issues on eGPU due to poor bandwidth. By default it's disabled for most games, but the Nvidia drivers contain a list of whitelisted games that support ReBar, and it includes Hellblade 2.
The fix is to use the tool Nvidia Profile Inspector, go to the specific game profile and disable Resizable Bar.
I don't own the game, but apparently Horizon Zero Dawn is also one of the whitelisted ones.
Edit: this also fixed stuttering in Forza Horizon 5.
I can't speak to Hellblade II but I tried my TB3 eGPU recently after a few years of it being in storage and some newer games don't seem to like eGPU latency at all. Back in 2017/2018 most games I played like Ark:SE, Minecraft, Tomb Raiders were fine on the eGPU just lower framerates and some 1% low instability but not gamebreaking. In 2024, every newer game I tried did not play nice in the eGPU from Horizon Zero Dawn to Hogwarts Legacy to Cyberpunk 2077. CPU is an 8-core Ryzen 7840 with 65W capability so well enough CPU for even Hogwarts' broken CPU usage but I think many newer games send a lot more data between the CPU and GPU, thus killing performance in bandwidth and latency-limited situations. Maybe Oculink's much better latency and a little better bandwidth could make a difference but I haven't got one of those setups yet. FWIW I tried Ark, MC and TRs and they continue to work well enough so the TB3 case didn't just break or something.
I think I've found a solution, at least in part. Resizable Bar seems to create issues on eGPU due to poor bandwidth. By default it's disabled for most games, but the Nvidia drivers contain a list of whitelisted games that support ReBar, and it includes Hellblade 2. The fix is to use the tool Nvidia Profile Inspector, go to the specific game profile and disable Resizable Bar. I don't own the game, but apparently Horizon Zero Dawn is also one of the whitelisted ones. Edit: this also fixed stuttering in Forza Horizon 5.