4.26 performance

I dont think they are. I have same results (sometime even WORSE) at least in editor and developer build.


The fix I mentioned in my post did make it to 4.26.2. Please note that it only applies if you are using DX11 as the rendering API. Your problems must be linked to other factors.

Have you verified what your bottleneck is? You can use the ‘stat unit’ command to have the engine display the timing for the Game thread, the Render thread (Draw) and the GPU. It would be interesting to get some data that compares those numbers in both versions.



@Svegn2 I’m using the fortress demo scene from the Lordenfel pack, in fresh projects for 4.25 and 4.26 with the same camera positions. I should note that performance in the Shipping build is similar between versions, the difference is noticed in the editor and Development build. Default RHI is set to DX11.

FPS: 114.99
Frame: 8.71 ms
Game: 2.70 ms
Draw: 3.90 ms
GPU: 8.71 ms

FPS: 99.77
Frame: 10.02 ms
Game: 2.52 ms
Draw: 9.21 ms
GPU: 10.00 ms

I understand that it’s a bit harsh because of the current overall situation and feedback.

The issue, as stated about a thousand times is:
the performance differential between the same scene across the 2 different engine versions.

in pie, out of pie, in developer publish, in shipping publish. All the same.

The previous engine (.25) just runs faster/better period.

This is for both dx11 and dx12.
With the exception that the drop of quality for the same scene in DX11 is slightly Less than for dx12

At this point, us listing OUR stat data for epic staff would be completely useless anyway.

The situation has to be triaged properly with consideration to all possible options.
Baked scenes, dynamic scenes, lpv on/off, Chaos on/off (granted this is a rendering issue as far as I and everyone here can tell).

On our - end user - end, it just seems like this situation is being completely ignored :confused:

Let me add…
Fortnite also has lower FPS output (same settings, same gameplay area) than before with same settings, by about the same amount we are all seeing in the engine.
And the GFX the vast majority still uses is a 1080TI.

Not 100% sure how drivers could potentially be at fault with different engine version here, but that’s worth nothing to properly triage.


FYI, for anyone running DX11 and experiencing the performance drop, try disabling translucency (ShowFlag.Translucency 0). this brought back performance for me without affecting rendering at all.

The other thing that worked was of course switching to DX12 in project settings, that gave me a good 20% boost in performance. Although still a bit worse than 4.25 unfortunately.

Hopefully that DX11 fix can make it in soon. fingers crossed

4.26 is a bit of a rocky release, but I’m sure it’s going to come right in the end. ‘if you want to make an omelet, you have to break a few eggs’ Development of something this complex is often 2 steps forward one step back.


I can confirm that ShowFlag.Translucency 0 restores most of the performance in 4.26.2 in the Editor and Development build.
I tested it also in 4.25 and it makes no discernable difference.

Hollup, but it just disable all translucency in UE: water, windows will not render without it.

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To know if that’s it you’d need to also disable the option in .25

If the cost doesn’t reduce at all in .25, but .26 shows a cost reduction, then there’s probably something to it.

I Uninstalled .26 so if anyone has both engines and can test this on the same scene / share screencaps you can probably help out @Svegn2 with the bug reporting…

Didn’t make any difference for me.

I have the same problem, is there any news about this yet?

Unfortunately, this also transfers to the shipping the problems. In the game I always had about 90 to 120 FPS. Now with 4.26.2 only 20 to 50FPS and when it comes up ca.65 FPS.

But it seems to have something to do with the shadows and DX11. With DX12 I have micro stutters without load.

I noticed something else, with the 25 version everything was ok. Even if you switched to DX11 and DX12. But when you switch to Visual Studio 19 the problems with FPS start. If you do 17 it is ok, if you do DX11 and 17 it is also ok. If you do DX11 and Visual Studio 19 the FPS drops immediately.

I think this problem has been going on for quite some time.


Epic could explain what’s happening here, even if there is no solution, but to make us understand.

Maybe one day…

Or make a way to at least “try” to open a newer project (i.e. 4.26) with an older UE version (i.e. 4.25), but no.

Yes, it would be nice…

At least what you could do now to get this problem reasonably under control.

No matter what you set or do, big jumps in fps don’t happen.

Fps keep going down the tubes.

What do you mean “even if there is no solution”? There is always a solution.
These UE4 problems especially with the shadows performance are ridiculous. Cryengine has a way better dynamic lighting, SVOGI, and shadows performance impact is minimal.
And now with the 4.26 version is even worse.

Or course! I meant something that they would consider a non feasible solution (because of priority, lazyness, or whatever excuse they would want to give us. But at least, and official excuse).

I already submitted it as a bug lot of time ago, with no response. Probably, the most of us reporting it, the most visible/prioritary this issue will be:

Hi, yes it will disable all tranclucency… but this reveals that 4.26 is rendering some translucent materials even if none are present in a scene. That’s why some scenes run much worse in 4.26.

In 4.25 it seems to automatically understand that there are no translucent objects and not waste precious ms on rendering that pass.


This could be the problem, translucency. Have you tried to test a map without any translucent materials, on and off?

I have found that SSAO hits hard, might be part of it?

Also, while it’s not this patch, I’d like to mention that updating instances is much more expensive in 4.25. Not sure if that’s the exact version, or if it’s one of the hotfixes, but I believe it’s 4.25.

Was wondering if anyone tried their projects in UE5 , and if there any performance changes there?

Yea it’s about 80% worse than ue4 .26