Help pleeease :( FPS drops out of the blue

superpef · Jan 31, 2023

Hey guys, appreciate any help to find the culprit. I am having a sudden drop in fps and just can't find the issue. Up until yesterday I was a VERY happy camper with solid 90 fps (only play in VR and need exactly that since 90 Hz is native refresh rate of headset) but since today it is all over the place between 80 and 90 which completely destroys the experience.
No changes in settings, no windows update, no NVIDIA update and no SOL, PURE or CSP updates were done before this happened. Today I then updated the Game Ready driver, SOL & PURE and keep having the same fps issue.

This is where it gets really weird: Fps are only unstable in online lobbies (which is what I play 100% of the time, mostly Nordschleife Tourist servers). In single player I can put max no. of opponents and fps are rock solid.

Specs/ Settings:

5800X3D - no overclock
4090 FE - no overclock
32 GB RAM @3200MHz
Reverb G2 at 100% SS via OpenXR with FSR upscaling enabled
Basically all AC and CSP settings max, PP filter enabled

DMAN · Feb 1, 2023

Have u tried Rolling back the driver? Sometimes its the fault of the manufacturer.

Johnny Speed · Feb 1, 2023

Seems to me that would be a issue with the server, internet connection, ect.

jkn87 · Feb 2, 2023

What a beast of a machine you have mate. It can't be your HW that's for sure

superpef · Feb 2, 2023

Thanks for the replies my dudes.

I have quit rolling back drivers a while ago, I find it more of a hassle to find and stay within a certain driver than to update frequently, at least as long as a problem isn‘t obviously connected to the driver. Would I have updated and then gotten the issue I would have rolled back..

Interesting that it can be a server issue, that has never occurred to me! Indeed today in a quick test session things looked great again!

Haha, thanks @jkn87. Amazingly though, after I upgraded from 3080Ti to 4090 I was shocked I still wasn‘t able to max out AC. Wasn‘t until I also upgraded from 5600X to 5800X3D that I now have a (almost lol) dependable solid experience while maxed out. VR is just absolutely brutal on the system at those resolutions. But yeah I tell ya, the first time I tried sim racing in VR I was immediately and completely hooked and lost any remaining common sense.

superpef · Feb 23, 2023

So just to report back on this issue. It really seems to have something to do with netcode/ server stuff. I am mostly fine but sometimes, e.g. when there's a lot of people in the Nordschleife car park, I get huge fps drops. I don't understand it but that seems to be it..

Lizard Of Bodom · Feb 24, 2023

Try lowering down Pure settings, I recently discovered that on one LAC server I can easily play with Max settings and keep stable 75fps where on another server i need to reduce Pure pre-set to high/medium otherwise it jumps from 60-70fps constantly. Same track, same qty of other players, just different server. odd but confirms theory about network problem side.

superpef · Feb 24, 2023

Not an option. I didn't sell a kidney + my better nut for my rig to keep having to play with and lower settings in AC. Also I found that it is either rock stable regardless of settings or not. If its unstable due to netcode, then lowering a few settings won't make it rock solid, at least in my case..

Lizard Of Bodom · Feb 24, 2023

superpef said:
Not an option. I didn't sell a kidney + my better nut for my rig to keep having to play with and lower settings in AC. Also I found that it is either rock stable regardless of settings or not. If its unstable due to netcode, then lowering a few settings won't make it rock solid, at least in my case..

yea, i get your point but just trying to say that some servers DO suffer from its own issues with CPU occupancy and performance and you may have i9 with 4090 and will still experience problems like in case of this LAC server i seen. Also lowering pure settings from ultra to "high" is not really THAT visually different

superpef · Feb 25, 2023

OK another update. I have found yesterday that I actually get better visual results + the ability to crank the absolute s*** out of resolution (supersampling) when I turn OFF PP filters. PP somehow messes with clarity even with identical resolutions in VR. My image is now absolutely insane and FPS headroom seems to be greatly improved. The only downside is break lights aren‘t visible without PP. Kind of a biggie sadly but I think I‘ll stick to this clarity for now..

Captain Beardface · Feb 28, 2023

Have a go using vrperfkit. I disable the upscaling and just use it for foveated rendering. In my headset I don't see any difference but it cuts down a good chunk of gpu frametime allowing for higher settings elsewhere. After copying the files to your assetto corsa folder edit the .yml to turn off the scaling option and turn on the foveated rendering.

For the clarity issue, its probable that your PP is using bloom. If you don't like that you can just disable it or change the brightness threshold in the config file (click 'manage' next to the filter on Settings>AC>Video) , and keep the rest of the eye candy.