I am using UE5 lumen for indoor environment, with a big 8K hdr for skydome,
translucent materials like glass, water together with opaque materials.
The problem is everytime when I switch from game camera to cinematic camera, the graphics takes a big performance hit.
It pops up “Video memory has been exhausted …xxx mb overbudget, expect extreme performance.”
I am using a 3070ti with 8gb g RAM and 8gb shared VRAM and 32GB RAM and cinematic engine scaling.
Downgrading to epic solve the red text, but black sampling noise starts to appear on a large white wall.
Lumen is a ray tracing rendering engine. Without knowing your cine camera settings and post processing, it’s impossible to say exactly what is causing the performance issues, but Lumen in general is about 40% as performant as the old UE4 rendering engine that didn’t use ray tracing. A 3070ti is a good card, but not powerful enough to expect 60+ FPS with UE5’s highest rendering settings. The sampling noise is the ray tracer unable to keep up with the framerate, meaning your card can’t render the frames in full fast enough leaving small artifacts.
If you want performance, you’ll need to sacrifice graphics fidelity. If you want the highest graphics fidelity, you need a better GPU.
As a troubleshooting tip, you can use the console command stat gpu to see exactly which render passes are running the slowest and optimize those. Also, make sure you’re using Hardware Raytracing instead of software raytracing.