Unlimited Performance in Unreal Engine 5 is possible!
The other day I had the luck to come across a really good article about Unreal performance by Daft Software.
It talks about disabling tons of Unreal features and using the mobile renderer on PC to achieve incredible performance. I had already been testing with using DX11 instead of DX12 for my small games due to potential instabilities, so I decided to try it out.
Yup, that’s 1005 FPS
Using lightmaps and limitations
In my case, I want to use lightmaps in my games, so I tweaked a little bit the settings to be able to use both lightmaps and some other features I like, but I’m liking the improvements.
This, of course, comes with some big limitations.
Say goodbye to Lumen, Nanite, Virtual Shadow Maps and all those other fancy rendering features. If its new and shiny, its out of the question.
But by leaving those behind, you get access to incredible performance.
One limitation of using the forward renderer, however, is the lack of screen space effects. In this case, what is more notable to me are the screen space reflections, which are completely missing from the forward renderer, so that might be a limitation to you.
Can this run on Integrated GPUs?
I did the first test on my laptop GPU, but then I got curious, how would a scene using this settings run on the integrated graphics card of the CPU?
To my surprise, being able to run at 244 FPS on an integrated GPU is something I would love. And that’s rendering at 2560×1600!
That being said, one of the limitations of the Mobile Renderer is that it does not support Indirect Capsule Shadows, and that’s a pity, as those make dynamic characters in a lightmap based scene really feel grounded.
D3D Mobile vs DX 11 + Forward
So here is what the same scene looks like using both Mobile Renderer and using instead the DX11 Forward renderer with Capsule Indirect Shadows. Both on the Integrated GPU.
Mobile D3D
DX11 + Forward
As you can see, there is a big drop in performance, but those indirect capsule shadows really ground the scene, and hey, 161 FPS on an integrated GPU at high res is a compromise I’m willing to take.
I still need to experiment more, but I hope this post gives you a little encouragement to play around with the ways Unreal renders the scene.
Thanks to the Original Article
Here is the article if you want to take a look at it, it’s written by a very talented person, so give them lots of love:
https://blog.daftsoftware.com/unreal-perf-maxing/#ok-so-how-much-faster-is-it
Full Comparison
If you are interested, here is the full comparison of settings which means:
- Discreet vs Mobile GPU
- D3DMobile vs DX11 Deferred vs DX11 Forward
Discreet GPU Graphics Scene 01
Discreet D3D Mobile
Discreet DX11 Deferred
Discreet DX11 Forward
Integrated GPU Graphics Scene 01
Integrated D3D Mobile
Integrated DX11 Deferred
Integrated DX11 Forward
Discreet GPU Graphics Scene 02
Discreet D3D Mobile
Discreet DX11 Deferred
Discreet DX11 Forward
Integrated GPU Graphics Scene 02
Integrated D3D Mobile
Integrated DX11 Deferred
Integrated DX11 Forward
By leaving behind the newer rendering features you get really good performance, even on an integrated card. These tests all ran at 2560x1600, so lower resolutions will run faster still. If you love everything about Unreal except its performance, it’s worth checking whether you can turn some of these features off and still get the look you need.
Recap
- The big wins come from turning off the expensive modern features: Lumen, Nanite, and Virtual Shadow Maps. Lean on baked lightmaps instead.
- The renderer choice matters as much as the features. The Mobile renderer on PC ( D3D Mobile ) was the fastest here, and DX11 tended to be steadier than DX12 for these small projects.
- Everything is a trade. Forward rendering drops screen space reflections and the other screen space effects, and the Mobile renderer can’t do Indirect Capsule Shadows, which is what grounds a character in a lightmapped scene. DX11 + Forward buys those shadows back at a real FPS cost.
What this doesn’t cover
These numbers come from controlled test scenes, not a running game. A shipping game spends its frame budget on gameplay, AI, physics, particles, animation, and streaming, so the headroom you see here is not what you’ll have once the game is actually doing something. Treat these figures as the ceiling for a given setup, not the frame rate you’ll ship with. All of this also assumes an art direction that doesn’t need Lumen or Nanite in the first place.
