Bug DLSS increases motion blur & other perf costs by over 5x

GPU perf: from 0.7ms to 3.7 in 4k. when activating DLSS.
The big perf increase happens in 1080 and 4k.
using 2021.2.4 DLS with Max quality mode & fixed screen %.

I just started using DLSS - is this normal and expected or a bug?
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edit: also seems to sometimes happen to Fixed Exposure and recordRenderGraph
to reproduce: Open HDRP template, go to interior room - turn on DLSS using fixed dynamic res @ 77% / you might have to do it a few times, close editor and retry, it doesn't always happen.

In editor. haven't checked if it still happens in a build.
RTX 2070 super
edit: case 1385924

 

I have same kind of issue. Happens in both Editor and builds. Not using Motion Blur, but Fixed Exposure.

 

PS: from my observation, it seems to decrease performance of all GPU operations; I also saw huge increase of costs for my own compute shader in GPU profiling. Sometimes it seems to resolve itself, sometimes not. Pretty erratic behavior. If it runs once fine, it seems to be stable.

 

Yeah, like you said, I noticed even LensFlareDataDriven gets 5-8x perf increase. Sometimes it happens, sometimes it doesn't.

 

PutridEx, did you report this bug?

 

Yeah, case 1385924
Although lately months can go on without a reply for bug reports

 

Was the bug accepted ? This bug makes DLSS unusable in current state.

 

No reply to the bug report yet, lately it takes months to get a reply...

 

I think it's not DLSS guys, enable Dynamic Resolution does this to me (although I used DLSS in that scene).If i uncheck only DLSS - nothing happens, only disabling dynamuc resolution altogether makes this extreme slowdown to go away

 

FSR is running fine for me, did not have a single incident with it enabled. It only happens with DLSS, didn't check the other algorithms.

 

maybe DLSS causes it in a first place, but after it had bugged (after running maybe normally for 5 minutes) - whatever I tried in that scene, including FSR, didnt work as intended. Reopening editor also doesnt help, it ruined dynamic resolution in this scene forever it seems. Only disabling it completely helped me. Frustrating

 

hm, okay, this problem I haven't encountered yet. Sometimes it also recovers from the DLSS issue, seems to be triggered by change of quality level.

 

@PutridEx Any news about this? Just tested 2021.2.12f1, Dynamic Resolution works again, but DLSS has same kind of severe performance issues. Sometimes it works, most of the time not. Hard to explain to users actually. @chap-unity DYK what happened to the bug report?

 

Still no reply to the bug report

 

This is kind of bad. DLSS seems not to be usable, at least in some sort of projects.

We constantly need to explain our customers that DLSS just works "sometimes", which leads to a lot of support overhead. @chap-unity any insights from Unity side?

 

@chap-unity were you able to repro?

 

QA replied to me, said they can't reproduce so case is closed.
I don't have access to an RTX card anymore, so can't do further tests, and frankly even If i did I'm tired of reporting bugs and only getting QA to look at it months later

 

This is kind of bad. We have thousands of customers who are able to reproduce....
That be said, it does not happen all the time, like roughly 50% of starts of the application, and issue often goes away if you change the HDRP asset during runtime.

As in our product FSR is working without issues, and we handle DLSS exactly the same, I guess the issue is not in our code.
@chap-unity Do you need any help in reproducing?

 

ok, sounds good. We don't use motion blur, as we are using VR, but issue seems to be quite the same. Basically GPU performance seems to drop heavily.

 

@chap-unity Any updates about this?