Question HDRP - Empty Scene Performance Problem (30ms CPU)

I have just downloaded the 2021LTS to give it a shot, and I started a new HDRP scene, without any changes to the settings.

Added a couple of cubes and tried running the game at 4K , and I get over 30MS in CPU time on the stats window - looking at the profiler the GPU is a bottleneck and since the cpu seems to be waiting for it.
If I go to FullHD instead i get roughly 60FPS with some drops to 20/30 randomly, with or without VSync.

The Specs of this machine is 1080 GTX and Ryzen 3950x with 64GB of ram - not the best GPU, but should still be pretty capable of running stuff.
I can ran "most" of the games I play on 4K@60FPS on Max Settings/Medium (GTFO, League of Legends, Satisfactory, etc...), but it looks like I cant run a empty scene in Unity? Is HDRP that heavy that a empty scene struggles to run on my machine?

Attached are some screens from the scene/profiler. Any help pointers would be apreciated - otherwise this is unusable for me at this time.

 

Bump.

 

Not normal, I have a GTX 1070 and I see very different results. This might be editor overhead.
Create a build with development mode and autoconnect profiler, and look at CPU performance in the profiler (make sure it's connected to the external game build).

 

Reasonable performance in HDRP is extremely reliant on disabling a bunch of features from the render pipeline asset that you aren't using, and carefully adding them back in only when you actually need them, and then further reducing the sample count on things like bloom, motion blur, etc. It's unfortunate but it is what it is.

 

Disabling the Volumetric fog brings things to a more reasonable FPS, but still, I expect the default settings to be usable on modern hardware. I tried disabling all of the Pipeline features (Removed all volumes, and changed the defaults on the editor for HDRP) and I get around 90/100 FPS. So this means that HDRP has 1/3 of the performance from URP, since I get 360FPS on a default URP scene? Is there anything else to disable?

I am trying to get a baseline for performance to see if HDRP is worth the switch.

 

I saw your post on Reddit.

as a quick note, in HDRP many processes are pre-calculated and accounted for in upfront costs, this is everything that's going on in your project settings and HDRP assets.

So an empty default scene is never empty, as it's projecting up to and beyond the camera culling, all lighting information and everything active in the project settings.

an empty scene in HDRP is also not a good place to start a benchmark either, because of this "infinite space" you'll end up using way more resources than a tuned scene. this is because HDRP uses physcially based calculations at scale, so you're calculating all that light and resources essentially infinitely, the games you're playing have already been tuned to performance, so it's by far not a good basis for measurement either.

You can refer here where we went into some more details

 

That is really helpfull, I am quite a noob on all of this SRP things. Any good resources to check about this? Like setup, practices, and considerations? Your post gave me quite a bit of insight on how this working underneath, but I feel I need to understand more - easier said than done, since I dont seem to find any indepth resources about it, or I am just not searching correctly!

Thank you for your knowledge!

 

Hey morphex, other than superficial content, we don't often find topics like this covered, but where possible we attempt to cover these topics. So if there's any particulars please do let us know.