AC: Stuttering reduction

[Rick Malm]

What can a user do to reduce or eliminate stuttering even in practice runs where their are no other cars on the track?

With Lotus F1 on Monza track I sometimes get as many as 6 stutters per lap, sometimes its 0 which is great.

What is the key cause of stuttering when running AC local vs MP which involves network response time as well as AC MP implementation?

Background:

My system: CPU: Intel i7-4770K Haswell 3.5GHz (some small amount overclocking was installed from Main Performance)
Video: NVIDIA | EVGA GeForce GTX 780Ti to 3 ASUS VE278Q 27” monitors 85hz refresh

I use a SSD memory for the AC install (The SSD is my C: drive)
My cpu usage is about 26% when AC is running. Processor Affinity shows all checked (0 to 8), Priority=Normal,
window resource monitor shows the cpus are getting used and none are any where near 100%, more like 40-50% and there are graphics showing PARKED cpus.

I turned off the car interior controllable items: no wheel, no driver arms.
I set Frame Limit to match my monitor max at 85.
FRAPS shows FPS will dip to 67 in some corners.
I tried reducing smoke generation and mirror resolution, I turned blur off completely.
I have not turn off HDR yet.
I have not tried to us msconfig and kill all background processes. I typically have firefox running in the background
which is the larger memory user (then Spyhunter4, explorer, LCore, office.bin, Steam....)
I have not tried to ALT-TAB out of AC when I see stuttering to see what is running with the resource monitor.
After I ran the resource monitor and looked at the CPU tab and saw a number of PARKED cpus I downloaded and ran a disable parking utility (edits the registry). This seems to have helped. Any problem with doing this?

http://coderbag.com/Programming-C/CPU-core-parking-manager

http://www.coderbag.com/Programming-C/Disable-CPU-Core-Parking-Utility

AC settings: Fullscreen Rendering ON | Triple Screen ON (6065x1080) | Vsync - OFF | Frame Limit - 85 | Aniso x 8 | AA x 4 | FXAA x 3 | Shadows -Low | World Detail - Maximum | HDR Color Sat On @ 92%| Smoke Generation – Low||Smoke in Mirrors OFF| Motion Blur - OFF | Mirror Resolution High| CubeMaps at Low | Faces per Frame - 4

 

[Rick Malm]

Strange results you having.

Fraps: Dont use it to capture movies or still but use this feature
Benchmarking Software - Show how many Frames Per Second (FPS) you are getting in a corner of your screen. Perform custom benchmarks and measure the frame rate between any two points. Save the statistics out to disk and use them for your own reviews and applications.

Click on the 99 FPS and notice where the benchmarks are saved, notice the hotkeys
F11 and F12 you might want to change to a keyboard key that AC does not use.
Notice the default is to capture both FPS and Frametimes.
Maybe sure it does not have the box checked Stop benchmark after ... seconds
Then start AC and it will put results in the default folder you noticed earlier.
When you hit the hotkey some time after the hickups if you want to just run to the end of the lap or laps. The benchmark mode had a counter in the upper left corner, I seem to remember the FPS counter in
the corner turns to green background characters if you stop the benchmark with F11 but I can not remember.

To view results dont bother looking at the raw cvs file but install and use
FRAPS Benchmark Viewer. I ran about 1/2 lap for you to see what the plots look like with 2 cards triple monitors which is a heavy load.

 

[Matheus Machado]

i have a steady 150 FPS during gameplay , fraps record with 30 fps ... hickups gone ! 5 laps no hickups . turn off fraps hickups there again !

What is your monitor? Also, What are your PC specs and AC settings?

 

[testdriver69]

W10, msi H97M-G43 , i5 4690k / 1x GTX 780 3GB/ m2sata ssd / 8GB ram
Singlescreen 1920 x 1080@144Hz, Fullscreen rendering: On / 4xAF /8xAA / FXAA: off / PP: on / Shadow: high ; Cubemap: static ; Vsync: off / Frame-limiter: off / World detail: max / Smoke generation: low / Mirror Res: high

thank you i will install the viewer and post a picture of what it looks like on my system

 

[testdriver69]

you know what, when i set my relay size higher i can dodge the hickups for a longer time.
I think it has to do with the replay size, when it is small it overwrites itsef ... right
i had it as small as possible but when i pump it up to 500mb i can do a whole lap without hickups... then they start again, when i turn down the replay size again i get hickups in first lap ! now that's new !! what do you think ? is this logical ?

 

[Rick Malm]

I seem to remember high Shadows will effect fps. I use Low

 

[Rick Malm]

Replay size: Anything is possible. I have had a repeatable crash when the replay size was TOO big
and I did a save replay when running 14 AI cars in a Quick Race for 4 laps.

 

[testdriver69]

i cannot get rid of the hickup problem with changing replay size, i can only influence the first appearing . enclosed my hickup lap - it was like 5 or 6 hickups but you can't see them on fraps

shadows on low, no difference .. maybe i should switch my monitor ? just for testing what happens

 

[Rick Malm]

Interesting that you can see the longer 8ms frametimes. I guess your high monitor rate of 144hz results in
a complex screen write while the 8ms happens. 1/144 = 6.9ms And you see some of the fps dipping
down to near 144. See if you can get your fps lows rate up with reduction in AC ingame options. No other ideas except to turn up clock rates. You might use MSI Afterburner and watch the clock rates.
I dont see a repeating pattern like I saw with a bad app.

 

[Rui Santos]

Report this on AC forum...

 

[Matheus Machado]

My suggestion based on the frame results and your monitor combination is putting the FPS limiter to slightly below your monitor refresh rate (about 136 FPS) and remove any overclock your processor might have, considering its a K version.

This will disable any amount of extra stress that is being put on the GFX card as your monitor can't display the frames you are getting and keep the performance stable while the monitor will display every generated frame properly.
Give me feedback on your results.

 

[Rick Malm]

Good idea. We used to do this on 60hz monitors so its a standard GOOD suggestion for faster monitors as well.

 

[testdriver69]

well monitor change did nothing, still the same thing back to the fast 144hz monitor .. cpu overclock is off and frame limit is set to 142,9 or 125 fps ingame... i tested both , no change... i will install the game on the same pc but w7 partition - i will report back

 

[testdriver69]

ok guys thank you very much for your support, it seems to be a windows 10 thing - i installed AC on W7 on the same hardware and the game runs superb ! no hickups stutter what so ever .

 

[Matheus Machado]

ok guys thank you very much for your support, it seems to be a windows 10 thing - i installed AC on W7 on the same hardware and the game runs superb ! no hickups stutter what so ever .

I had the same issue when updated it, make sure you run AC in a secondary desktop.

 

[Alan_Bernardo]

i cannot get rid of the hickup problem with changing replay size, i can only influence the first appearing . enclosed my hickup lap - it was like 5 or 6 hickups but you can't see them on fraps

shadows on low, no difference .. maybe i should switch my monitor ? just for testing what happens

I know for me OV1 causes stuttering. Each update I try the app-- it's a very good one, so I keep hoping-- but immediately upon install the stutters start. When I delete the app, they stop.

I've tried the tach, fuel, all the different components. Every last one of them, whether singly or in combination, cause stuttering.

 

[testdriver69]

thanks for your input but in my case i have no apps running , even disabled the ac built in ones - like i said it runs perfect on windows 7 - same pc different HDD ( no ssd btw) lets see if this is fixed in the near future . i guess it is a driver thing,
i only had rsr live timing plugin installed, but i deleted and documents folder and installed fesh so ther should be no app running

 

[Rick Malm]

Glad you are running ok.
I have RSR and acti (motec logging) and several AC apps running like I mentioned earlier and got 1 hickup running 14 car quick race of 4 laps. I am bothered more by the grip that I lost or something that changed with the 1.2 update. Lap times down 1 sec per minute (actual lap time from 2014 at 53.9 down to 54.15 in early 2015 release and then to 54.4 in June after mid spring and with 1.2 I am now down 55.2. Maybe I drop RSR until they reset it again and not having it install might remove that jerk that I get once and awhile.

 

[Lou Sytsma]

Possible solution for Nvidia Card users in Nvidia Inspector set the max pre-rendered frames to 1 and see if that reduces stutters.

 

[Rick Malm]

Good suggestion, its what I have in the Nvidia control panel under 3D settings for acs.exe and global setting as recommended by Main Performance PC when I got my new system. I once posted settings recommended by Main Perfomance PC in this thread and have not changed them since then.

 

[Rui Santos]

Isn't this stuttering problem solved with the last 1.2.2 update? Check last one...


1.2.2
- Fixed acd files reading wrong values creating problems with 4WD (possibly other cars)
- Corrected Nissan GT-R Nismo fuel tank capacity
- Corrected Nissan GT-R Nismo auto clutch assist engadgement
- Corrected Nissan GT-R Nismo weight figure on Interface spech data description (does not affect physics)
- Corrected Nissan GT-R Nismo skins' names.
- Added skin template for Audi Sport quattro
- Improved Audi Sport quattro skins
- Fixed Alfa Giulietta argento skin
- Fixed BMW Z4 red skin
- Corrected low fuel consumption for Lamborghini Miura, adjusted for the rest of the bonus pack cars
- Corrected Audi Sport quattro S1 turbo pressure dial
- Added DAMPER_MIN_LEVEL in assetto_corsa.ini to allow for some residual FF damping once the car is moving (default is 0)
- Small tweak to relaxation length variation vs tyre load
- Corrected Abarth 500 and S1 semislicks tyre heating and small corrections in alignment and bumpstops
- Fixed ghost car
- Corrected Alfa Romeo 155 DTM setup antiroll bar missing, plus some minor adjustments in suspension geometry and differentials
- Added ksBrakeDisc shader to allow modders to implement glowing brakes
- Removed log messages for Python function "getTexture" because some python app dev thought: "Hey, what a nice function! I will call it every frame instead of caching the result" resulting in >60mb logs and stuttering and 10 years less in the life expectance of the AC support guys