Why does real time reflection cause a 65% fps loss in HDRP

Unity Engine
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1

Hello,
I’m working on a racing game and my scene is really full, but only when there is no real-time reflection of the car in the scene, the fps value I get is around 50 - 60 fps. When I activate real time reflection, the fps is around 10 on average. Ok, I don’t have expert knowledge in unity at the moment, but even though I turned everything off, I couldn’t find any improvement.

I even made two identical scenes to compare this to you in UPR and HDRP. You can see the fps values in the picture.

While there is a 20% loss in urp, there is a fps loss of almost 65% in HDRP. An empty stage and 50fps in just a real time reflection. This seems really weird to me. I never thought I’d run into trouble in such a strange place after I had come this far.

By the way my video card is gtx 1650

Anyone have this problem or overcome it?

8147984--1058219--Reflelction Proble issue.jpg
8147984--1058219--Reflelction Proble issue.jpg2178×1414 497 KB

2

Because it draws the scene a second time? Also, do performance tests in builds.

3

URP also does this process every second. What will I observe with the performance test?

4

Unity’s editor is heavier than it looks.

5

I built the game but it didn’t matter.

6

URP uses uses frame slicing (splits the amount of work over multiple frames), HDRP does all the work in a single frame, every frame.

In 2022.2 (maybe 2022.1 don’t remember exactly) HDRP will also get the same slice feature for realtime reflection probes.

But yes compared to no time slicing reflection probes in URP, HDRP realtime reflections are more expensive than usual.

7

Then I will download 2022.2 and try it, I will post the results here. Also, URP mirror reflection can be adjusted, but HDRP only offers full resolution.

8

ı downloaded 2022.2 version and yes there is a slicing options and it’s realy working. I hope this feature will come to other versions soon.

This is 2021.3.2f version there is no slicing and avarage fps is 25 -30
8155016--1059641--upload_2022-5-25_11-42-15.png

2002.2 versiyon slicing off and fps is avarage 20 - 30
8155016--1059647--upload_2022-5-25_11-43-12.png

2022.2 slicing is active and fps is around 50 -65

8155016--1059653--upload_2022-5-25_11-43-43.png

9

I wouldn’t count on it. LTS releases by their nature will receive bug fixes backported to them but if this qualifies as a feature it won’t be backported. Last project I was involved with used the HDRP and we had to constantly migrate to new releases.

10

After all, isn’t the 2022 version a top or new version? So there is no possibility of the features we see here coming? Yes, unfortunately I keep my expectations low, but it is a very important feature.

11

You’ll see it in future releases. I was more commenting on the LTS release you were on previously.