Performance going downhill with latest versions of Unity, Post Processing and SRP

So I started a new mobile project in 2020.1 with Universal RP.
While prototyping and setting up basic systems I did my first build and deployed to mobile. I was very disappointed when almost an empty scene with very basic post processing (just a color lookup) couldn't keep 60 fps on mobile.
My previous project could run at 60fps with post processing so I decided to investigate.
It turns out that the performance was going downhill since Post Processing Stack V2 was introduced.

I've tested these scenarios:
1. Unity 2018.4.3f1 built-in renderer:
- Standard shader
- Standard + Post Processing Stack V1
- Standard + Post Processing Stack V2
- Mobile Bumped Diffuse
- Mobile Bumped Diffuse + Post Processing Stack V1
- Mobile Bumped Diffuse + Post Processing Stack V2
2. Unity 2020.1.0a13 built-in renderer:
- Standard shader
- Standard + Post Processing Stack V1
- Standard + Post Processing Stack V2
- Mobile Bumped Diffuse
- Mobile Bumped Diffuse + Post Processing Stack V1
- Mobile Bumped Diffuse + Post Processing Stack V2
3. Unity 2020.1.0a13 Universal Render Pipeline with built-in Post Processing
- Lit
- Lit + Post Processing enabled
- Simple Lit
- Simple Lit + Post Processing enabled

Test scene looks like this:


I tried to keep the quality and player settings as close as possible between projects. All materials use Diffuse + Normal maps. All PostProcessing profiles are only using a 16 LUT for color grading (StackV2 and URP versions set to Low Definition Range).

I've run the tests on Xiaomi Mi A1, and I've also checked on Nokia 6.1. The results were basically the same:


Oldest Unity 2018 works best with oldest Post Processing Stack V1. Switching to Post Processing Stack V2 results in FPS dropping by 10-15 (below 60).
Unity 2020.1 is visibly slower than 2018 using any Post Processing. I assume that a bit more complex scene, and it will be visibly slower without Post Processing as well.
Unity 2020.1 with URP and built-in Post Processing is the worst.

Wasn't URP supposed to have like better performance than everything else?
How come that a 2-3 year old Unity runs better on mobile than anything currently does?
What's up with PP Stack V2 being so much worse than PP Stack V1?
How come I can't run the simplest scene with the simplest color grading at 60 fps on mobile?
I have so many questions and so much frustration...
What's going on?

 

It is better performance but the settings in URP are not the same as the settings in other pipelines so it will run slower if you do the same settings. You should perceptually adjust them to look the same, then it will run faster. If it doesn't run faster, Unity considers it a bug.

Pretty sure its a problem on your camera or post effects or setup.

 

Here are the settings:

Spoiler

Here's the camera:

Spoiler

Here's the PP Volume:

Spoiler

 

Which SRP options do you have to "perceptually adjust"? There are not that many options, I turned everything off or dropped as low as possible for the tests. Are there any other places I should check for options?

 

Stop NaN can be unticked from camera. but I don't see any bad settings there. I can only assume somehow the resolution changed.

This is bad news for such a simple example. Perhaps Unity can look into it? This is only with post effects on right?

 

Make sure only one volume is in scene for testing. It can be easy to layer them these days (for example a sneaky default Unity one might be present too).

 

Stop NaN have almost no effect. Tried with and without it.
There's only one volume, yes. I've checked.

 

Please report a bug

 

1 Disable Stop NaN
2 In URP Unity force depth pre-pass when post processing is enabled, even if you don' using depth based effects.

 

Sorry, I'm not exactly sure how to enable depth pre-pass? Is that the "Depth Texture" checkbox in the URP profile asset?
I tried to enabled it just now - the FPS with post processing remained the same. The FPS without post processing dropped below 60, so it doesn't seem feasible to keep it 60+ with DepthTexture and PP enabled.

And by the way when the Depth Texture checkbox was disabled in URP profile asset, the Depth Texture option on the camera said "On (Forced due to Post Processing)". So it seems it was being forced all along.
Also, for some reason even if I disabled Post Processing on the camera, the "On (Forced due to Post Processing)" doesn't change.

 

Try to disable shadows. Shadows force depth pre-pass too.

 

Also, AFAIK, URP on Android does an extra blit if you use post atm (although it will be fixed sometime in the future).

 

Yep although this isn't really a huge problem unless in VR, as it prevents certain other features like foveated rendering from working.

 

Shadows were disabled in all tests.

I've reported a bug with all the test projects zipped.

Not really sure what to do next...

 

Make sure to post a link here when/if the issue goes up on issue tracker.

 

thanks for sharing this
Can you please include 2019.1 or 2019.2 in your tests?

 

Just finished testing 2019.2.14f1. It showed exactly the same results as 2020.1.
I believe 2019.1 won't be much different.

 

There is a need for some serious improvements right now with mobile in general, but especially with mobile VR. It is very hard to get post processing working with mobile VR, and even harder to get it working at a high frame rate. Some people suggest not using any post processing, but post processing really helps certain visuals.

Similarly, mobile VR has the option to use Multipass, Single Pass, or Single Pass Instanced. However, Single Pass Instanced in nearly completely broken, and Single Pass does not work with most post processing on mobile. So mobile VR developers are largely stuck with Multipass, which is the least performant option.

And has anybody ever gotten Vulkan to work with any Android device? I have not. I would love to be able to use Vulkan with mobile VR like the Oculus Go and Quest.

 

To be honest I'm completely baffled. For several years SRP is one of the main buzzwords at any Unity event and there are tales of PC grade graphics available on mobile. Yet I create an empty scene with the cheapest post processing option and performance plummets through the floor. How come this wasn't discovered and fixed ten times over?!?

How come Post Processing Stack v2 runs 10 fps lower than v1 out of the box on an empty scene, yet it becomes the standard for all Unity versions forward like everything is fine?

What am I missing?

 

I still wonder, why everyone are think that URP is a mobile optimized render pipe? Yes you can run boat demo on super phones at 30fps, but its' mean nothing.

 

Because that's how it is advertised. You get HDRP targeted at hi-end hardware, and URP, which is scalable down to mobile. Since it is a better structured and optimized pipeline than the built-in one, one would expect that it would run AT LEAST as good as the built-in pipeline, not worse.

 

Emphasis mine.

If URP has less features and is slower what is it good for?

 

I'm happy we have chosen to go back to 2018.4 all newer versions sucks

 

https://forum.unity.com/threads/post-processing-v2-cpu-performance-concerns.542322/#post-5235431

The above thread is probably what you're missing, and something I didn't realise as I haven't had a production project on new postprocessing yet. TL;DR - Unity's PPv2 volume code, which runs even without more than one volume, looping through enormous managed lists every frame

Thanks for reporting the bug - unfortunately this effects anyone using Unity's new post-processing backbone, PPv2 or otherwise...

 

HDRP for high-end PC, URP for low-end PC and super phones. All true. Nowhere says URP is for potato-phones.

 

JFC, this is ridiculous
The initial post is dated Jul 2018... No one seems to care anymore

 

Can you read?
When upgrading a project from the built-in render pipeline to the Universal Render Pipeline, you should expect similar or improved performance

 

That's why we all moved to SRP because of the way they advertised it.

 

Glad it is not just me screwing something up. I've noticed worse performance in general after trying out our project in 2019.2, 2019.3, and 2020.1. Going back to 2018.4 but also considering trying out 2017 if it doesn't have anything that will break the project by going backwards.

 

I would so use 2018.4 with PP Stack v1 for the new project, but considering that 2018.4 support ends in ~1 year, it would be safer to switch to a newer version.
I'm really surprised that the overall performance degradation with the base Unity 2019, but also the PP Stack v2 and Lightweight/Universal RP on mobile didn't make much more noise in the community.
I mean, at every Unity event you hear these crazy numbers of mobile games released each year using Unity. How come no-one's talking about the performance? How come these issues haven't been looked at?

 

because they all use unity 5.6 lol

 

Something really strange just happened to me as we decided to try 2018.4 before downgrading the whole project I decided to benchmark 2018.4.13 PPV2 built-in pipeline against 2019.2.5 PPV2 LWRP 6.9.1
Surprisingly the later was faster and by alot

 

Phone used for benchmark Xiaomi mi 8 lite
2019.2.5 LWRP 6.9.1
Average : 37fps min : 7fps max : 53fps

2018.4
Average : 28fps min : 3fps max : 35fps

 

Draw Call : 300 - 1350
Tris : 200k - 800k

 

I haven't tested LWRP, since it's not supported any more.
I've tested 2019.3 today with URP and the results were identical to 2020.1 with URP.
Can you please test your scene in 2019.3 with URP or 2020.1 with URP?

 

Sure
I'll try tomorrow

 

EDIT: cleaned up a very very long rant about the current state of SRPs and unity in general.

TLDR version is that I am very very tired of fighting the engine for about a year now and the time spent on this vs our project is laughable. I am a unity fanboy at heart for a long time but that is being tested right now. I also get a general sense of the community as a whole being less defensive of unity based on current state of play.

 

The weird thing is that HDRP feels much more solid these days, and it's the one that is still in preview.

I know I often complain about most of Unity being perpetually in preview, but if actually releasing a feature doesn't mean anything, it stops us from having something to look forward to.

I guess there was pressure to release LWRP/URP since they announced that they will stop improving/deprecate the built in renderer, but there is a solution to that. Don't drop support for stuff before the new solution is ready, then take your time and release rock solid features we are excited for.

 

Strong agree on all points.

 

@Devil_Inside didn't have time to test 2019.3 or 2020.1
But after more test in 2019.2 I have come to conclusion that LWRP perform well and here is some tips
Don't use static batching
SRP Batcher help sooooo much for scenes with many draw calls, I've been able to run some scenes with more than 1M, more than 2000 draw calls and shadow(only directional light) at 15-20fps@720P
Vulkan is buggy and unstable can't rely on it

 

@buFFalo94
The problem is that, as far as I understand, LWRP is deprecated and won't be updated/supported any more. URP is the way forward, so if you're going to change to 2019 LTS at some point, you'll also need to change to URP.

In your case though, I think URP will work equally as well for you, since, it seems to me, with a heavy scene like yours, your bottleneck is somewhere else.

The scene I've tested was super simple, so unless I missed something super obvious, there is some kind of problem with the newer Unity/PP Stack/URP.

 

I can only agree that everything gets worse with every new version. I regret switching Unity 5 where everything was fast, the runtime and the editor. Since 2017 its just regression by default and nobody cares. Switching to 2019 and urp decreased the performance by 50%, the app size grew, less devices were supported and it's often not even running on the supported devices anymore. It's Really sad .

 

Agreed
But it's too early to switch to 2019.3 it's too buggy and as far as I know URP is in the same state
So as for now we got almost everything working with LWRP except shadowmask but I saw an hack from someone who managed to make it work thus we won't wait for Unity to add it

 

Which Unity version provides multipass for URP, please ?

 

I don't know. I am currently using 2018.4 with multipass.

 

With URP?

 

No, not URP.

 

Thats what everyone is talking about here though

 

It was expected when the development went so fragmented and non unified, now is just a race to fix bugs and handle problems, plus create multiple projects when we should not have to.

Overall is a nightmare comparing to the old stable unified Unity and getting worse with every version. I really cant grasp why rename LWRP to URP only few weeks after it finally came out, all this is like a huge pre-pre Beta thing going on with us testing it.