ACC Graphics and Performance Discussion

Troubles with getting g-sync/freesync to work in ACC.

I just upgraded to a Gigabyte G34WQC monitor, 3440x1440 max 144hz, freesync premium, GPU is a 1070.
G-sync is enabled in Nvidia driver, freesync enabled in the monitor OSD.
Using RivaTuner and a build in FPS counter in the monitor, I have confirmed variable refresh rate to be working in Dirt Rally 2.0, Assetto Corsa and F1 2019, but ACC refuses.

My relevant settings in ACC are:
Resolution: 3440x1440
Fullscreen: enabled
v-sync: disabled
framerate limiter: tried both off, 144 and other settings.

Game will run at 70-100fps according to RivaTurner, but monitor is locked at 60fps.
In the other games, those two fps counters in RivaTuner and monitor build in would be in sync.

Any hidden settings, or something else I am missing?

 

Low framerate at sunrise regardless of settings

I'm playing on Ryzen 7 + RTX 3080 at 1440p. Regardless of the track, if I play in the middle of the day in clear sky I get 90-100 fps. When I race in rain I get 80-90 fps. But when I drive at sunrise I get 45-55 fps regardless if my settings are all on Epic or on Low. When I start the race at 6:00am the first 2-3 laps before the sun shows up on the horizon are in terrible 45-55 fps and then suddenly after the sun is on the sky the framerates jumps back to 90-100 fps. I tested that in Epic and Low settings, with high and low number of AI on the grid, with and without the mirror.

Does anybody have any idea why the framerate drops so much right before the sunrise? There are no sun rays to render, no complex particles or reflections, nothing that would justify such a drastic fps drop. Any idea how to fix it except not racing so early in the morning?

 

my settings for Nvidia panel:
https://i.imgur.com/BNlgjok.jpg
https://i.imgur.com/GOzDbCQ.jpg
https://i.imgur.com/NctOJzU.jpg

Game:
https://i.imgur.com/XTALzPf.jpg
on a freesync 3440x1400 100Hz it works.

 

Just guessing here, can it be the physics simulation taxing the CPU as the temps change on track and conditions change a lot as the sun rises?

 

No it's really the stretched shadows and quick change in light conditions that tanks the performance, the physics engine is running the same level of work if temp change or not imo. It's graphic pipeline related imo and it's the CPU/RAM that is the bottleneck in that scenario.

@fotoplastikon what is your Ryzen 7 model? What RAM are you using?

One thing that helps it to disable shadows completely, if you want to get rid if them add the following to engine.ini in %localappdata%\AC2\Saved\Config\WindowsNoEditor

[ConsoleVariables]
r.LightFunctionQuality=0
r.ShadowQuality=0

I know it's less beautiful, can be off putting for some, but if it's a competitive race, at least you'll get much better frame rate to defend your chances.

 

So I was looking for CPU benchmarks for ACC, and found this:


Tested with a RTX 3090 in Francochamps with 50 cars in the rain.

https://www.purepc.pl/test-procesor...zy-rocket-lake-kontra-reszta-swiata?page=0,23

 

Two questions i couldn't get an answer by searching...

1) Is there any way to force foliage to the lowest lod possible at all times?
2) Is it possible to disable the/adust car lods? I'd like to disable the best quality lod for all cars and test performance.

Both Settings in the graphics menu only affect the distance at wich the lod is selected.

 

Found one way to force the foliage to the low LOD.

foliage.ForceLOD=5
foliage.DitheredLOD=0
(if the set value is higher then the available LODs, the highest lod is selected)

foliage.ForceLOD only allowes the selected LOD to be displayed (foliage is going to pop out when it's far AND when its close). foliage.DitheredLOD at 0 breaks the programming by using an invalid value, thereby forcing all Foliage to be displayed at all distances. Works best with ingame foliage lod at very low.

Eliminates all foliage pop-in. Ragged af, but it kinda works. Great for VR. Very slight performance uplift.

r.ForceLOD at 5 brings another very slight performance increase (2-3%), but i couldn't see any difference. Have to investigate that one further

 

I’ve tried so hard to escape it but I’ve finally decided to live with Vsync…unless anyone can give me one last thing to try please?

I run a 4790k with a mild all core OC to 4.4ghz, 16gb 1866 ram and a 3070.

I haven’t swallowed the high refresh pill as to me, resolution and graphics still trump high frame rate for me, having not experienced it. (On a related note to this, watching someone play a game for a few minutes via teamviewer then going back to 60fps vsycned is glorious!).

on my 4K 40” tv I can easily hold well above 60fps with settings I am happy with.

unfortunately, no matter what I do, only vsync on is totally smooth. I’ve tried frame limit on with various settings and with it off. It finally seemed locking at 60fps was the solution but it still doesn’t work all the time.

I’ve tried every single suggestion on line and like I say, vsync on is perfect but a touch of input lag. Now the input lag doesn’t slow me down (as much as the stutters might be doing) but I’d still like rid of it.

what happens is my FPS never wavers from 60 without vsync but even though it’s smooth most of the time, I can see the frame time going higher and lower than 17ms. Sometimes as high as 20ms and sometimes as low as 10, which I didn’t think possible. CPU seems ok, maybe 70% max on one core but it stutters even when cpu load is low.

All background apps are shut down.

any last things I can try? Thanks

 

Cap your FPS in RTSS / MSI AB like i show in this video.
Look at the frame time graph, this is with V-Sync on, the graph is messy and frame time is jumping all over the place, once i cap it, it turns to a solid 16.6ms.

 

Personally I'm running ACC on a 60 Hz monitor without Vsync but with the RTSS 'async' limiter set to 60 FPS (front edge sync might be suitable also). From my testing unlocked is too variable, vsync can introduce latency and can lead to framerate drops, and the in-game framelimiter is not stable either. However, even with the RTSS limiter in place the variance in ACC on my hardware isn't great (seen as a one thick line in the frametime graph, even when the unlocked framerate surpasses 100 FPS), though the frame pacing is steady with the limiter in place. Either way the RTSS limiter feels the smoothest. I have tested ACC with DXVK and the limiter in pace, which resulted of a variance of just 0.1 FPS and a perfectly flat line - but DXVK leads to lots of loading stutters and freezes in the menus and when entering a session.

One thing I have noticed though, on my system regardless of framerate limiter there is a visual stuttering that doesn't manifest in frametime graphs, may be similar to the "stuttering in turns" others reported. The only solution I've come up with is pressing F11 to window ACC, alt-tab out and in again, maximising ACC with F11 again. Just alt-tabbing doesn't work. Then visual stutter or skipping is gone for the rest of the session. Occurs across different patches, game installs and Windows 10 installs. No idea what causes this.

 

thanks I’ve tried this

 

This used to be my method in AC and it seemed to work a bit in ACC but inconsistently. Will try it again

 

The whole thing makes no sense to me. I realised I was running my GPU at 50% on the settings I had so FPS was not an issue.

just tried 1080 with only 10 opponents and it runs smoothly. Tried the same at 4k pretty much max settings and I get 90% GPU usage.

managed to keep the frame time to rock solid 16.6 but it still stutters and it stutters more, the more eye candy there is, despite rock solid 60fps 16.6ms.

gpu is running fine temp and clock wise

 

You are CPU limited, DDR3 and 4790k doesn't cut it for high frame rate in ACC, a 5600X with DDR4 3600 would improve your fps significantly

 

I can hold over 60fps all the time in bad weather at night with a decent size grid.

How am I CPU limited?

 

Try Nürburgring with 24 cars at sunset and tell me your over 60fps.

 

Purely anecdotaly, I’ve got no hard numbers, but I’ve just upgraded from my 1660ti to a 2070 Super. I run in 1080 res but in stereoscopic 3d on a projector. With this new card (and ALOT of faffing around getting drivers to work properly again) I’m able to run nearly everything on epic and have working mirrors and still keep a butter smooth and rock solid 60fps. Previously I was on mid to high settings and no mirrors and would fluctuate between 45-60fps.
Very happy with that.

 

Not saying I’m able to hold in every situation known to man but when I am holding 60fps at Spa at night in the rain with AI, how am I cpu limited?

I mean yes, I am CPU bottleneck but not to the point of not getting 60fps.

I’m asking how my cpu can be the cause of stutters when locked to 60fps

 

ACC is demanding a lot to ram (for both latency and bandwidth) and to CPU, the 3070 is definitely more capable than what your CPU/RAM combo can chew.

I've had 4790K in the past with 1600 cl9 and a GTX 1080, sidegrade to 2700X with my 1080, then 1080ti, it was slightly better sure, but nothing spectacular, very similar CPU IPC.
Drop in upgrade to 3700X was significant, much better IPC.
Drop in upgrade to 5800X was huge.
From 2700X to 5800X always had 3600c14 RAM.

Of course, we can't compare graphics settings, I'm running pretty low graphics as I'm running VR in the Reverb (2160x2160 per eye @90Hz) so it's GPU intensive as well, but to get very good 0.1% (where you feel most of the stutters) and 1% lows, you need a beefy CPU/RAM combo, you could have a 3090 with your current PC it wouldn't fix the stutters imo, you would have a lower GPU usage and only marginal improvement in frame time pacing.

Try to use CapFrameX to analyze frametimes on a replay file, and try to identify and decrease CPU intensive graphics settings.