AssetBundle performance regression

I found that 2020.1.0b9 has serious asset load performance regression compared to 2019.3.13f1
I saw something like that in the known issues, but I think this is a different issue.

I see this on PS4 and Xbox One.
I'm talking about a load time increase from a few seconds to half a minute.
We load everything from lz4 compressed asset bundles.
(I don't know if the regression affect Windows or not but even if it does it is still fast enough.)

Are there known issues about this?
The ones in the release notes doesn't seem to match (MacOS only, reported against 18.4 etc.)

 

I will investigate further.
I'm no longer sure it is AssetBundle related.
I see long pauses so I'm hoping I can capture something during that time in Razor or Pix.

 

I tested after updating to 2020.1.0b10 and I see interesting results.



Here you can see 1 frame that takes 8 seconds.
Looks like async loading is no longer async in 2020.1 ...

 

It was too large to attach even compressed, so here it is:
https://www.dropbox.com/s/zpay5te2plsue68/PreLoadingGlitch.7z?dl=0

In this capture it was 11 sec

I put in Log calls and what I found is that all this happens BEFORE we call LoadScene for our loading screen...
So I have no idea what is being loaded here and why

 

Thanks for the tip, I'll check.
(I'll have to revert to a previous version of our code, because we are depending on a crash fix arrived in b12.)

 

Tested with b7 & b8 and I see the issue in both.
I do believe that this happens before we call AssetBundle.Unload actually.

It looks like that the assets that were loaded up to that point are loaded again for some reason.
I believe this happens on PC as well, but they are loaded from disk cache (from memory) which makes it too fast to notice.

I'll experiment a little bit more, but I might be able cut out enough assets from the project so that I can send a bugreport.

 

I tried to cut assets that we don't load to create a testcase ...
... and it reduced the time of the pause
It makes me believe that all assets are loaded from the open AssetBundles.
We have no LoadAll calls anywhere in our codebase.

I checked and the issue also happens on Windows build, but it takes only 346 ms. That's why I haven't noticed before.

 

And I finally arrived to the conclusion that it is NOT a Unity 2020.1 regression at all.
Something changed in our project shortly before we switched to 2020.1
I'm still tracking it down, but looks like the issue will not really be relevant in this part of the forum