5.3.1 +50% vram usage?

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Hi all!
We have a gaming project with a huge and complex map. In UE 5.2.1 the built version uses 8.9 GB VRAM, meanwhile in UE 5.3.1 the built version of the same, otherwise unchanged project uses 13.4 GB VRAM (I have a 4060 Ti with 16 GB VRAM).
We need to disable ray tracing in the UE 5.3.1 project to be able to work effectively in the editor now because of the significantly more VRAM usage (in the editor it consumes more than 18 GB now).
This phenomenon can be observed in smaller maps too (approx +40-50% VRAM usage).
We checked it with Render Resource Viewer too, where we experienced the same numbers.
Anyone has any idea what can cause this?

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Yeah, and the issue is there with the newly released 5.3.2 too, the Engine and the any kind of packaged builds are eatin’ up VRAM like there is no tomorrow…

What the hack is going on here?! :woozy_face:

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Definitely a huge issue even with top tier PCs. My 4090’s VRAM is almost full with our latest project and before 5.3 it was easily handling the load because it was about half this big before…

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While we haven’t noticed any unusual increases in 5.3.1, we did have many Landscape issues relating to VRAM usage in the past. Here’s some things we looked at, maybe they can help:

Which Landscape features are you using? Things like the Water Plugin or Landmass Blueprint Brushes? How many edit layers are you using? → These things all require intermediate data in the editor, so unfortunately they can take a huge amount of VRAM to run.

What resolution does your Landscape have? → Some things don’t get handled too well like non-Power of 2 Landscape sizes. There is a fix for it, but it’s not yet live afaik

What texture format was used for importing the height map? → 5.3 now warns you when you use .r16 raw instead of .r8 raw for instance. However, I think Unreal converts it to its format on import anyway, but it might be worth checking in a fresh UE project to see if you can reproduce it

Are you using 2x2 component size for your Landscape? → 2x2 currently has some bugs, so I wouldn’t be surprised if that would also have some memory oddities

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Thanks for the suggestions!

  • No Water Plugin
  • No Landmass Brushes
  • 1 Edit Layer
  • Texture format should be fine
  • 1x1 component size

Things that can be an issue:

  • Size is non power of 2, as the Landscape was resized from a larger, square sized one to a smaller, non-square sized one

Problem is, the Resample feature does not work at all, in 5.3 so we can not resample the landscape to try things :smiley:

It is 63x63, 1x1, total components are 9x9, and resolution is 568x568

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A 568x568 Landscape sounds fairly manageable. Due to the Power of Two limitation, it should internally be handled as a 1024x1024 Landscape which should take ~120MB + some extra memory for the Landscape Material.

Have you confirmed the VRAM usage of the Landscape with a tool like the RenderResourceViewer (Available via the Tools dropdown and searching for “Heightmap” and “Weightmap”) or Unreal Memory Insights?

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We have no landscape in our levels and we’re seeing something like this as well. Levels with barely anything in them at all (half a dozen actors with 1 or 2k textures on them) and it’s using 7.5/8gb of dedicated VRam. Loading another level with the same thing in it, and during the loading of the level VRAM usage spikes to 10gb/16 on the shared vram, but then drops back down to 0.2 shared after loading.

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I had same problem. do you got any idea to deal with it?