Kunos Assetto Corsa CPU Occupancy > 99% Warning Advice

Paul Jeffrey

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Assetto Corsa 99% Issue.jpg

Kunos Simulazioni respond to recent CPU Occupancy > 99% issue with new advice for PC owners.

Following the popular update to build 1.12 of Assetto Corsa on Windows PC, Kunos Simulazioni have quickly realised a small proportion of users are suffering from a return of the CPU Occupancy > 99% issue that plagued many players during early builds of the game.

The return of the issue, attributed to amendments to the controls.ini file received in the latest build, has been acknowledged by the developers and advice has been issued on how to resolve this problem for the vast majority of players. With the update to the controls.ini file Kunos have brought to the game a more detailed FFB feeling for a number of wheel users, unfortunately this has caused problems for some players, especially those with older or home made wheel solutions. With the below advice issued today by Kunos the Italian team are confident any remaining CPU Occupancy issues will be resolved.

It is advisable to contact the official Assetto Corsa PC support forum if you still experience this issue after following the below steps.

FOR PC/WINDOWS USERS
With the new v1.12 update, we have introduced a new section in the "controls.ini" file located in your "Windows Documents\Assetto Corsa\cfg" path called "[FF_SKIP_STEPS]", that manages the force feedback update rate. The default value is now "0" instead of "1" and it overrides the old value located in the "assetto_corsa.ini" file (in the Steam game folder). This brings a more detailed force feedback and a better driving feeling. If you experience "CPU OCCUPANCY > 99%" warnings, please tick "Half FFB Update Rate" in the the UI Options -> Controls -> Advanced and this will bring the value back to "1". Not all the steering wheels can manage the maximum update rate, so no worries.

If you are using a very old steering wheel like the Microsoft Sidewinder or Saitek R440, or other hand-made ones, you need to open the "controls.ini" file, and set the "FF_SKIPS_STEPS" value to "4". It should look like this:

[FF_SKIP_STEPS]

VALUE=4

This should solve any "CPU OCCUPANCY > 99%" warnings related to the force feedback refresh rate.

Please always double check this value if you load controls profiles created before v1.12 update! In case, please create a new controls profile with the proper value!


Assetto Corsa is a racing simulation built for PC, Xbox One and PlayStation 4. The game is available to purchase now with a number of additional DLC packages available depending on the chosen platform.

Assetto Corsa 99% Issue 1.jpg
Assetto Corsa 99% Issue 2.jpg

Assetto Corsa 99% Issue 3.jpg


The Assetto Corsa sub forum here at RaceDepartment is the place to go for Assetto Corsa news and community discussion. We have a whole bunch of mods to download, a specific area for modders to discuss their WIP projects and of course our epic Racing Club and League events. Head over and join in today.

Have you experience the 99% Occupancy issue? Does the above suggestion resolve your issues? What do you think of the 1.12 update? Let us know in the comments section below!
 
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Thank you very, very much! It solved my problem. Since I upgraded my PC from a Core2 Duo to an i5 7570, this problem always happened. The frame rate was OK but the simulation seemed to be in slow motion. I have an old steering wheel (Microsoft Sidewinder FFB wheel). Changed the FFB_SKIP_STEPS setting to 4 as suggested and it solved the problem perfectly. Thank you very much!
 
Did those guys do something with the tire modeling during the last build?
I took what is usually a great combination in AC... the 458 out to Mugello last evening and it just felt really, really bad.
I then took a few laps in the GTR and it just 'pushed' like crazy, even at 30 kph the car was sliding.
It was actually difficult just to keep the car on track...even at those very low speeds.
One of the benefits of VR seating, is the ability to more accurately compare vehicle movement directly with vehicle speed since the speedometer is easier to see and read.
A 458 or GTR will not slide at those speeds...heck! my Saab 9-3SE on regular Sumitomo road tires doesn't do that.
I'll have to try again today to see if it was just a fluke.
 
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Did those guys do something with the tire modeling during the last build?
I took what is usually a great combination in AC... the 458 out to Mugello last evening and it just felt really, really bad.
I then took a few laps in the GTR and it just 'pushed' like crazy, even at 30 kph the car was sliding.
It was actually difficult just to keep the car on track...even at those very low speeds.
One of the benefits of VR seating, is the ability to more accurately compare vehicle movement directly with vehicle speed since the speedometer is easier to see and read.
A 458 or GTR will not slide at those speeds...heck! my Saab 9-3SE on regular Sumitomo road tires doesn't do that.
I'll have to try again today to see if it was just a fluke.
drop psi mate (about -5), you will see they're too high
have you checked that ?
 
Whoever in 2018 still has CPU occupancy issues, I strongly suggest to head over to the offical Kunos technical support forum and create a ticket with a copy of your log files.

You will be sorted out quickly and know precisely what the cause is.
Posting here is a bit sketchy as for some people who have this problem the cause is different from other people who had it in the past and share their measures to fix the issue THEY had.

Especially for people who have a rather powerful machine and have this issue - head over to the support forum and sort it out there.
The support forum also allows very nicely to search for CPU Occupancy and while you are waiting for a response allows for you to try fixes that helped other people already.
 
It's not occupancy issues in terms of getting a warning in AC for me but FPS performance being pathetic due to high single thread load and AC is unable to feed the GPU enough.

Tried:
old UEFI and newest with Meltdown and Spectre patches, disabling/enabling Meltdown and Spectre patches for each, no difference
audio channels 256 vs 32, no difference
using keyboard, no difference
using gaming device with FFB on it disabled as in it should not report FFB support (though registry seemed unchanged so maybe it was not processing the FFB but still reporting FFB support), no difference
FF SKIP in system and user INI files, 0, 1, 4, 40, no difference
name displayer on/off, no difference
cleaning all unused python apps from AC and it's configs, no difference
PP yebis preset, some difference but fairly negligible, default Kunos preset is slower by about 2-3% compared to my own preset (tested with x86 variant)

This does make a difference, a big one:
x86: 65% GPU utilization, 95% main_T CPU utilization (single thread bottlenecked as always), total CPU utilization 60% in monitoring 80% in task manager, 132-136 fps single player (depending on mood, probably due to random main thread allocation to a specific core though as far as I see in monitoring the main overloaded thread is jumping between all cores), 60 fps multiplayer

x64: 96% GPU utilization , 94% main_T CPU utilization (single thread bottlenecked as always), total CPU utilization 60% in monitoring 81% in task manager, 190-200 fps single player (depending on mood, probably due to random main thread allocation to a specific core though as far as I see in monitoring the main overloaded thread is jumping between all cores), 100 fps multiplayer, 45% GPU, 91% main_T, 62% total CPU, awful as always but at least as awful as it used to be and not even more as x86 is now

They definitely borked something and x86 is unusable anymore because if they did apply a fix that fix was only done to x64 executable and x86 is left to rot. The CPU load is almost identical yet x64 variant seems to perform fairly close to what x86 used to long ago, there is some issue with x86 not being able to feed the GPU enough but x64 seems to work considerably better.

If someone for some reason (mods, apps, overlays, ...) still needs to use x86... you're royally screwed with AC in that regard and switching to x64 at least gives you back the poor performance AC used to have instead of what awfulness Kunos has made now their x86 variant do. The difference is massive in terms of GPU utilization and the effort to update to x64 variant is worth it. x86 variant is borderline unplayable now, especially online.
 
It's not an OS thing, 64bit systems that support 64bit on hardware and OS level have been around for over a decade even before owning 4GB+ RAM was needed. AC doesn't use anywhere near 4GB RAM from what I have seen and that's the only major difference difference between x86 and x64. Neither did x64 in AC work flawlessly from the start hence it was better to stay with x86 until issues are resolved, now it has turned the other way around. Sure you can optimize and use specific "hacks" for each variant but in the end the only difference often is that each variant is compiled with either x86 or x64.

And even today x86 is still more compatible overall when you need to mingle applications together. It's getting better for x64 but it has taken over a decade as the need for x64 from a common user perspective is relatively small.

Your CPU is running in compatible mode anyway so that it can run 32 and 16bit applications as well. Plus most/many applications even in 64bit OS are still 32bit, why? Because there is no benefit of using 64bit with it's higher overhead unless you need tons of RAM as web browsers, photo/video/audio editors may need, small utilities? Often have no need for large RAM amounts.

x86 support is here to stay for a long time still, as long as x64=amd64 lives so will x86.

Obviously minimizing draw calls (objects, scene complexity) in AC always helps to reduce CPU single thread bottleneck feeding GPU, but not easy to do as a user with available settings.
 
My Assetto Corsa is having this same problem of PCU occupancy 99%, I changed the value of the option "Windows Documents \ Assetto Corsa \ cfg" path called "[FF_SKIP_STEPS]" inside the file "controls.ini" from 0 to 1 or 4 as I said and even so it didn't solve my problem it still occupies the CPU in 99%, I have a Logitech G29 steering wheel and I've tried everything to solve this problem and I don't find a valid solution.
 
My Assetto Corsa is having this same problem of PCU occupancy 99%, I changed the value of the option "Windows Documents \ Assetto Corsa \ cfg" path called "[FF_SKIP_STEPS]" inside the file "controls.ini" from 0 to 1 or 4 as I said and even so it didn't solve my problem it still occupies the CPU in 99%, I have a Logitech G29 steering wheel and I've tried everything to solve this problem and I don't find a valid solution.
I'm also facing this problem from the last couple of days when I reinstalled AC. Don't know what should I do. My config is enough for this game (Using i7 8700 with RX 5700xt and 16gb DDR4 RAM) and I guess this is not a hardware issue. Sometimes the game works fine for 1-2 races and then "CPUoccupancy >99%" happened.
 
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