4.26 performance

Development Rendering
61

take your pick from the possible culprits.

  1. chaos.
  2. new shader model for the engine with included emissive lighting.
  3. skylight updates.
  4. volumetric cloud updates.
  5. the same bad raytracing stuff for over a year despite Nvidia releasing branches they could pull and include code from right in this very forum
  6. post process changes / Engine quality switches.

It’s really a free for all. And they don’t really seem to care because “fortnite runs” so…

1 Like
62

Somebody mentioned that you could use the legacy shader over the new shader model , but i have not been able to figure out how to change this , anyone know how?

63

Any update on this? 30 fps drop on same project with this VisibiltyCommands ms eater in GPU stat.

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I read somewhere (I think it was Unreal Slackers) that there is known rendering performance issue which is going to get resolved probably in next hotfix. I don’t know if it is related to these issues but It could help. There seems to be indeed issue when so many people are complaining but saying just “my fps is now low” is usually not enough to properly tackle this issue. If possible please try to profile and check stats and post also comparison of these from 4.25 and 4.26.

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There is new fps killer in GPU Stat called VisibiltyCommands which taking almost 2-3ms (on rtx 3070) in 4.26 comparing to 4.25.

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Is there anything that can be changed or done about it to get FPS back? I mean what is “VisibiltyCommands” ?

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Speculation in the visibility commands thread was that it is hardware occlusion queries.

Easy way to test is to just turn it off.

68

Make triple sure that the beta SSGI isn’t enabled too.
not sure if I had turned it on, or if it wasnon by default (which being Beta definitely should not be).
the cost is still really high compared to .25.

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I was using SSGI on previous project aswell (with half-res). In GPUStat only difference is VisibiltyCommands (and it takes 3ms).

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Where do you turn it off?

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“Occlusion Culling” in project settings.](Visibility and Occlusion Culling in Unreal Engine | Unreal Engine 5.3 Documentation)

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Hmmm , i will try it .

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Didn’t help me at all. Thanks for pointing me to it though.

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The question is: When you disable it, is Visibility Commands still eating up GPU frame time?

I wouldn’t necessarily expect it to improve your framerate by turning it off, I only suggested it as a test. If you can determine that Visibility Commands is indeed the hardware occlusion culling then you can try to optimize it by flagging only large objects to be set as occluders.

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I don’t know i just tried it , haven’t looked closer yet. I tried so many things now , maybe i’m just looking for the magic bullet to up me my 20 to 25 FPS back again. :slight_smile: But probably there is no magic bullet.

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Use unity. Or .25 :stuck_out_tongue:

77

Do you try r.RayTracing.ForceAllRayTracingEffects 0 ?

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Currently ray tracing is not enabled.

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Hi everyone,

I just wanted to let you know that we have fixed a performance regression in the D3D11 rendering code. This is only for the editor but will fix the issue where the VisibilityCommands and ShadowDepth stats are higher than before. This fix will be live in the upcoming 4.26.2.

Those of you working from the source of the engine can grab the following commit from GitHub: https://github.com/EpicGames/UnrealEngine/commit/d69ec2eb90d7d6be4683abbc9a9d9841c36dabed

Regards,

Martin

2 Likes
80

Thanks for the Update !

We also have found out that the performance drop was only happening in Editor. Maybe some others here can confirm that the performance is fine in a packaged game ?