Question Huge 50% performance drop 7.5.2 -> 10.7.0 (12.1.2)

I'm using HDRP to create screenshots and videos of my game. I'm using Unity 2019LTS and HDRP 7.5.2 but due to small shadow and flickering issues, I decided to try new versions. I opened, converted the project to new versions and I got a huge performance drop without changing anything on my side. These are the results:

Unity 2019LTS and HDRP 7.5.2:

Unity 2020LTS and HDRP 10.7.0:

Unity 2021.2.7 and HDRP 12.1.2:


What could be the reason for these big performance drops?
Are there any new settings introduced that are heavy in new versions and can be disabled? Because I don't see any visual improvements, only performance drop.

 

First thing worth knowing is where's the bottleneck/increased performance. Is it on the CPU or GPU?
You can find this info using unity profiler and enabling GPU & CPU module and comparing between the two versions.

Notice that if GPU is the bottleneck, CPU will still be higher because it will be "waiting" for the GPU. I believe if that's the case, you will find an element taking a lot of performance named "WaitingFor...." that's not the full/correct name since I forgot, but it's something similar and has Waiting in its name.

You should do this test on a build, editor CPU performance can have overhead. Although GPU is consistent perf metrics are consistent in editor and build.

Honestly, even with the new features, I feel like the performance shouldn't be that different. Maybe something within your project, or HDRP causing this perf diff. If we know where the additional performance is coming from, it'll be easier to track.

There's a good chance that the performance between these versions will be similar in a build, and it's only different when playing in editor, so that's also worth checking out.