script change in b8 takes 50% longer to compile+reload than in 2020.1.17

Same script, same project (5x test for average):

  • 2020.1.17 takes 9 seconds
  • 20201.1b8 takes 14 seconds

That’s 50% longer iteration time and when the task at hand requires a lot of back and forth, you do notice productivity declining severely.

I know that asset conversion and prefab are much faster but unfortunately I am not building scenes, I’m in the middle of optimization which involves slashing through a lot of code and verifying performance and breakage, where iteration time is so important to allow to go back and forth between Rider and Unity many many times. I was hoping that the listed optimizations would cover this and speed my iteration time which in turn would make this more productive.

This regression was introduced in 2020.2 and plateaued with 2021. I think it’s assembly reloading that has become much slower in the past 6 month.
It’s probably deeply rooted and I don’t expect it to be fixed in this release but I logged a case anyway (1317926) and gave your team access to the full project. I hope it helps.

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2021.2 updated Roslyn to 5.0.102, NetCore to 5.0.2

I wish this being updated in 2021.1Beta to get more time saving experience with scripting

I just noticed that 2021.1b8 and 2020.2 idle at 30% cpu usage


hot idle is logged as 1318384
slow reload+compile is logged as 1318387

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Hi @laurentlavigne ,

We were able to reproduce the regression and are investigating:
https://issuetracker.unity3d.com/product/unity/issues/guid/1317926/

The second report is still pending evaluation but I have pinged the team about it.

Thanks a lot for your help!

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FYI we have created this forum post/thread " Improving Iteration time on C# script changes " to communicate about our progress on fixing these regressions.

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