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]

My game cpu just hung. Hoping it will come back. I can remember the transparency anti aliasing setting off the top of my head.

Ok, I give up. reboot, Anti aliasing Transparency if OFF.

 

[Ace King]

Hi Rick....i see it wasn't mentioned here so i will tell you what i done which completely eliminated my stutters!

Go to steam/steamapps/common/assettocorsa/system/cfg/dx11.ini, now edit the MAXIMUM_FRAME_LATENCY=0 and change it to a 1

 

[Blkout]

My game cpu just hung. Hoping it will come back. I can remember the transparency anti aliasing setting off the top of my head.

Ok, I give up. reboot, Anti aliasing Transparency if OFF.
View attachment 57285 View attachment 57286

I always use multisampling, I don't think you will see a performance hit but it makes transparent textures look better, things like fences and trees. We've done just about everything you can do Rick. I think you're just seeing the limits of a single 780ti on triple screens. AC is a very pretty sim and its pretty taxing because of it.

 

[Rick Malm]

So what do this var do? I will try it.

 

[Rick Malm]

Blkout, Thanks I will try multisampling. Yes this a very pretty sim and
and really enjoy it, just trying to get as much out of it as possible.
Thanks for your help.
R

 

[Blkout]

Wish there was more I could do, I'm an overclocker so I always get as much bang for my buck out of my hardware but I realize others don't always feel comfortable with that. For your setup though, I would have your CPU running at 4.2 - 4.4GHz, and your 780ti running at 1150-1200MHz. That would just about guarantee at least 10fps more than what you're getting now.

 

[Rick Malm]

Main Performance did my PC and overclocked it but they did not give me a spec. I think my keyboard would have to be moved from USB2 to 3 to get it to allow me to look at the bois and I just have never done it since putting the wheel and keyboard on USB3 were causing random loss of wheel and keyboard input. Is there a simple app that will tell you those closing numbers? (or ratios if I remember thats how its done)

 

[Karl Brankin]

What is your video memory usage ? If I recall the 780 ti has 3gb video ram ? Maybe try turning down 4xAA to 2xAA. I know things like Battlefield 4 start to push 3GB RAM with triple screen resolution and 4xAA.

I use triple screens with crossfired AMD Sapphire tri-x 290's which have 4gb ram and use 2xAA as it keeps it nice and smooth,

 

[Rick Malm]

Blkout or Karl,
Video ram on 780ti has 3Gb,
Sorry I am not smart enough to know how to check usage of it.
Can you advise on how to check the usage?
Can you advise on how to verify overclocking amount on the cpu and gpu?

I will try the 2xAA setting

 

[Rick Malm]

Well guys, I tried 3 races, 3-6 stutters/lap after the following changes
Before this I was at most getting 1 and so if I can get back to that I would
be very happy.
Since then I changed
1 Transparency off changed to multisample
2
steam/steamapps/common/assettocorsa/system/cfg/dx11.ini, MAXIMUM_FRAME_LATENCY=0 and change it to a 1
3 4xaa -> 2XAA

I give up for the day.

 

[Blkout]

Rick, I only said to try multisampling transparency antialiasing. If its causing you framerate issues, by all means go turn it off. I'll type up something to verify your CPU and GPU speed in the morning. About to hit the bed for the night. I do not know what that app ini changes, first Ive heard of anyone changing that setting so maybe go back to default setting on that too.

 

[Rick Malm]

Ok I started backing up one by one.
1 Transparency back to OFF. Still to many stutters. about 6-7 stutters per lap
Happens on fast tight corners (lots of background changes)
e.g turn 3 and 4 and sometimes out of 6 at Monza almost for sure when lots of movement.
2. Turned MAXIMUM_FRAME_LATENCY=0. Still stutters
3. back to 4xAA. Same issue, same number of times.
4. Disable HDR, Same issue
5. vsync back to off from adaptive. Maybe little more tearing, same amount of stutters.
6. HDR back on. all smoke off. 7 stutters per lap
Used fraps on last run and counted them. (min 71 max 85)
Wish I would have used FRAPs on every change tested.

 

[Jason Hunt]

Is this during a race or practice and qualifying? I had major stutters due to the AI pitting on two release builds, with certain car and track combinations. Less stutters in the race as the AI doesn't pit as often as practice or qualifying.

I identified my issue by watching the fps meter (blue line peak = dropped frames) as the AI entered the pit.

I posted my findings on the official forum and the problem went away with the next build. However, as it was only certain cars on certain tracks I half expect it to come back with a different combination and/or they make a slight change to AI path finding (assuming that was the cause).

This might not be the issue in your case but worth checking. I have also started to suspect frame issues under cornering i.e. when the physics calculations are ramping up and I started noticing this during the last 2, maybe 3 main builds. But I don't get obvious stutters - just a slight feeling the game is struggling.

Also, max frame latency wants to be 1 not 0.

 

[Martymcfly]

Hi Rick
My advice to you is if you want to get the most out of this beautiful Sim then you need to get to know your PC a little bit better. It will take a little more time but you have some nice hardware there and you have to do a little bit of googling and tweaking your PC to tame all that horsepower. Especially with your triple screen setup which can be a bit harder to find the sweet spot settings for all that resolution. Download Afterburner 3.0 to help you see what your CPU and GPU are doing. ( and turn that vsync back on! ) with one 780 and triple screens u need vsync on.
Learn how to Overclock. Start with your GPU. After a bit of googling and going on tech forums you will be able to Overclock your GPU with the push of one button. It's that easy. Then go for your CPU.
You will definitely see a boost in performance. And Rick even after weeks and months of fine tuning your nice machine you will still get the occasional stuttering here and there. This game really stretches our CPU 's to the limit. In time it will get better through better drivers and new builds sent to us every week. And by then your beautiful PC setup will be all ready to run it silky smooth. It will take a bit time that's all....

 

[Blkout]

Also, max frame latency wants to be 1 not 0.

What is the default setting? I'm inclined not to change this setting because mine is at default and I get no stuttering.

 

[Michael Hornbuckle]

For as much as you paid for a Main pc it should already be overclocked. (I promise you overpaid big time)

Just keep playing around with settings, eventually you will find what works smoothly for you...and with that pc and card, there is a magic setting for sure.

Having monitors that are 85Htz instead of the usual 60 or 120 is probably why vsync isn't working for you.

 

[Martymcfly]

For as much as you paid for a Main pc it should already be overclocked. (I promise you overpaid big time)

Just keep playing around with settings, eventually you will find what works smoothly for you...and with that pc and card, there is a magic setting for sure.

Having monitors that are 85Htz instead of the usual 60 or 120 is probably why vsync isn't working for you.

That's what I thought at first too.
I would limit my frames to 85 and turn on vsync in settings. if you still get screen tearing then limit frames to 60 with vsync on. There should be no tearing.
You will still get occasional stuttering though. That is different than screen tearing. Also Rick I noticed that you mentioned that CPU is barely hitting 50 % usage. That is highly suspicious with this game. Your CPU should be hitting between 90 to 100 usage on all 8 cores. And when your cores hit a 100 % usage that's when usually you get the game stuttering slightly. Your GPU is probably stretched to its limit pushing those three screens as well.

 

[Rick Malm]

Is this during a race or practice and qualifying"
Jason:
See these issues during practice and and quick race (5 laps) 6-7 stutters/lap and some minor tearing.
Ok back to using max frame latency wants to be 1

Marty: Downloading Afterburner now. Trying to decide
which vsync to check (Nvidia or in game) I will mess around with both.

Michael:
I do limit my fames count to 85fps and will turn vsync back to adaptive
which will limit me to 60fps.
Do I also check in game vsync? I dont have it checked now.
Yes total cpu is only 30%. Images attached. Notice average of other cpus is not that high but some peach now an then at 100.

 

[Michael Hornbuckle]

I use the in-game vsync....

 

[Martymcfly]

The in game Vsync works fine.
Once you download afterburner go into setting and turn on CPU monitor settings and GPU usage, memory, temp and so on..
looking at the CPU task manager picture you definitely hitting 100% usage at times.