Unreal Engine 4.21 is out, now defaults to the Vulkan API on Linux

For comparison, if anyone knows, does it default to DX11 or 12 for Windows?

I booted on the Windows I'm keeping for downloading plugins and compiling. Here is a screenshot of the menu that answers your question :

Thanks, but unfortunately the image isn't showing :)

For comparison, if anyone knows, does it default to DX11 or 12 for Windows?

I booted on the Windows I'm keeping for downloading plugins and compiling. Here is a screenshot of the menu that answers your question :

Thanks, but unfortunately the image isn't showing :)

You can download the image and open it on your computer. In any case, it lists the targeted RHIs as (and this is a simplification of mine): DX11, DX10, OpenGL 3, OpenGL 4, Vulkan Mobile, Vulkan Desktop. I don't know which one is set as default, but there is a checkbox marked only for DX11 and DX10.

My follow-up question is: what could be the reasons why they haven't set Vulkan Desktop also as the default for Windows?

My follow-up question is: what could be the reasons why they haven't set Vulkan Desktop also as the default for Windows?

I'm no expect by any means, but watching from the sidelines I see that any non-DX11 renderer appears to have trouble keeping up. This suggests to me that their engine is heavily designed around DX11. So heavily that other backends yield sub par performance. If this is indeed the case, then their core engine may need massive changes to make it match better with the likes of Vulkan (and DX12). So it may be quite some time before anything can beat their DX11 support in performance.

Compiled and tried it today. Maximum FPS that I'm getting is ~30 frames for a simple scene. I remember it was the same when I tried Vulkan when it was introduced for the first time in UE4. Although, editor seems to be running fine.

Does anybody knows if there is something that can be done to improve performances?

They designed the Windows on DX11, Linux on OpenGL, now Vulkan and Mac On Metal.
But don't worry, the engine has a pipeline for every platform, so it can optimise every time. The only thing that matters is "SM4, SM5, or mobile" ?
Btw, from what I read en hear from them, they are more interested in Vulkan for Win / Nux / Mobile.

Compiled and tried it today. Maximum FPS that I'm getting is ~30 frames for a simple scene. I remember it was the same when I tried Vulkan when it was introduced for the first time in UE4. Although, editor seems to be running fine.

Does anybody knows if there is something that can be done to improve performances?

Make sure your kernel and graphics Nvidia drivers are up to date. Lock your CPU governor in performances mode. If you are working on performances, you can activate the tools. In console (set the key combination in editor preferences then SHIFT+F1 to unlock mouse then your keys) PROFILEGPU, stat fps, stat SceneRendering, stat game are your friends lol. Performances are always lower in editor.
In the editor, you have the blueprint machine running, the editor windows and your preview if you open it.
It's a LOT.
If you really want to try your project, use the "standalone game" mode.

Have fun ?
If anyone is interested in rendering technics and where they are available, you can read this :
https://docs.unrealengine.com/en-US/Engine/Rendering/SupportedRenderingFeatures

Meanwhile on ARK:SE's upcoming features (since 2016) "Linux - Vulkan support". Here's their chance. But we all know that Wildcard will fail to take advantage of it.

Not that I'm defending Studio Wildcard for their Linux port but it's a lot more to port Ark to Vulkan than a basic UE4 update. Their engine is highly modified and upgrading isn't like installing the new engine, loading the game and tweaking, it's a major undertaking to actually port the new code in the new engine and maintain all their custom code for the game. It's highly unlikely we will see any major improvement as they surely are not getting a lot more sales from Linux clients. It doesn't honestly make sense for them to do all the work involved in porting the engine over to make it happen on a game that likely won't result in many if any more sales. Also, UE4's Linux support is less than ideal to be quite honest. Many devs have a large number of issues so honestly, you can't logically put all the blame on Studio Wildcard, some of that blame goes to Epic. Many of the massive graphics glitches in ark such as the rain, caves, dust, etc was a Linux OpenGL renderer problem that happened to be fixed on accident when they upgraded the engine right before releasing out of EA. I wish for a Vulkan port but realistically I wouldn't hold my breath.

Wait are you telling me that they finally tackled the psychedelic rain glitch? And why am I not at all surprised that it was fixed by accident? Anyways I have long since given up on that game along with any other DRM malware. Just for the record, I think that Wildcard have a great team of artists and the original concept of ARK is brilliant. However, ARK's consistent bugs and breakages led me to the conclusion that their programming/engineering team are a bunch of talentless monkeys.

Compiled and tried it today. Maximum FPS that I'm getting is ~30 frames for a simple scene. I remember it was the same when I tried Vulkan when it was introduced for the first time in UE4. Although, editor seems to be running fine.

Does anybody knows if there is something that can be done to improve performances?

Make sure your kernel and graphics Nvidia drivers are up to date. Lock your CPU governor in performances mode. If you are working on performances, you can activate the tools. In console (set the key combination in editor preferences then SHIFT+F1 to unlock mouse then your keys) PROFILEGPU, stat fps, stat SceneRendering, stat game are your friends lol. Performances are always lower in editor.
In the editor, you have the blueprint machine running, the editor windows and your preview if you open it.
It's a LOT.
If you really want to try your project, use the "standalone game" mode.

Have fun ?
If anyone is interested in rendering technics and where they are available, you can read this :
https://docs.unrealengine.com/en-US/Engine/Rendering/SupportedRenderingFeatures

Thank you for your answer!
Yes, my drivers run games through Proton without any problem. CPU governor can't help at all because, I tested it on a simplest scene with UE4 default first person template.
I understand everything, but the same scene should produce above 150 fps inside of editor on my system. I have enough experience with UE4 after using it almost every day last 2 years.
I tried to find something in editor and project preferences that could help, maybe, but nothing changed 30 fps.

Compiled and tried it today. Maximum FPS that I'm getting is ~30 frames for a simple scene. I remember it was the same when I tried Vulkan when it was introduced for the first time in UE4. Although, editor seems to be running fine.

Does anybody knows if there is something that can be done to improve performances?

Make sure your kernel and graphics Nvidia drivers are up to date. Lock your CPU governor in performances mode. If you are working on performances, you can activate the tools. In console (set the key combination in editor preferences then SHIFT+F1 to unlock mouse then your keys) PROFILEGPU, stat fps, stat SceneRendering, stat game are your friends lol. Performances are always lower in editor.
In the editor, you have the blueprint machine running, the editor windows and your preview if you open it.
It's a LOT.
If you really want to try your project, use the "standalone game" mode.

Have fun ?
If anyone is interested in rendering technics and where they are available, you can read this :
https://docs.unrealengine.com/en-US/Engine/Rendering/SupportedRenderingFeatures

Thank you for your answer!
Yes, my drivers run games through Proton without any problem. CPU governor can't help at all because, I tested it on a simplest scene with UE4 default first person template.
I understand everything, but the same scene should produce above 150 fps inside of editor on my system. I have enough experience with UE4 after using it almost every day last 2 years.
I tried to find something in editor and project preferences that could help, maybe, but nothing changed 30 fps.

Weird... This doesn't happen on my machine with 4.20.3.
I will try 4.21 soon. I hope this won't happen
btw, when I told you to check your driver, I meant games don't usually need the last engine version but the editor is always built around the last Nvidia driver available. They always insist about that.
Did you try to package a test project so we can see if it's coming from the Editor ?


Last edited by Jau on 10 November 2018 at 3:09 am UTC

About the Governor, if you don"t have a very recent kernel (and even then) you can have some trouble. Not very important, but I had some laggs (I had an I7) opening projects or test while having many blueprints + animation tabs open. If I put the governor on "performances" : no more.
Now, I'm using a recent AMD and Linux 4.19. I still put this in "performances" mode but honestly, I didn't notice anything.


Last edited by Jau on 10 November 2018 at 3:06 am UTC

About the Governor, if you don"t have a very recent kernel (and even then) you can have some trouble. Not very important, but I had some laggs (I had an I7) opening projects or test while having many blueprints + animation tabs open. If I put the governor on "performances" : no more.
Now, I'm using a recent AMD and Linux 4.19. I still put this in "performances" mode but honestly, I didn't notice anything.

It wasn't happening on 4.20. Everything worked fine. At last, almost everything. Recently I found things that don't work at all - I wanted to make game menus to work with game controller, but no. It doesn't read values of axes when in menu designer (I forgot how it's called, UMG editor?). I was hopping that it's maybe fixed in 4.21, but 4.21 is working like I described. First I thought that you ware already using 4.21 and that my case was an exception. I never had to "overclock" my CPU to be able to use UE4. I have an i7 and it was always more than enough to run UE.

I wanted to test a test project before trying to open my main project in the newer version, so I just made a simple first person project.

Edit: I'm currently on Ubuntu 18.10. And with 396.54 driver.


Last edited by Power-Metal-Games on 10 November 2018 at 3:15 pm UTC

Some news !
4.20.1 works great but you need to open it with -opengl .
When you want to test your project at full performances, just open it as "standalone game".
Gamepads work perfectly too.
One more thing : Epic told me NOT to use 415 ! This beta driver is unstable and not supported by Unreal Engine. I ran some tests and yes, I can confirm a lot of trouble with many Vulkan products.
0 problems with my project ! PS4 gamepad is super reponsive and FPS locked at 60 with all my post-processes and emitters ! I'm relieved :P


Last edited by Jau on 17 December 2018 at 1:59 pm UTC