25% FPS loss out of the blue

[Billy Pilgrim]

I'm looking for a bit of help.

A week or so ago, I started getting 20 to 30% fewer FPS when using AC. I wondered if it was Dynamic Shaders so uninstalled it but that doesn't change much, if anything. I can't figure it out. (the fps drop didn't come just after installing Dynamic Shaders anyway)

Wondering if a Windows update may have done this. I can't think of any graphics-type mod that I installed a week ago either.

I've got a 1080 ti and an i7 4770k (with an overclock). Triple screens. But there has been no hardware change recently that could have caused this.

 

[RasmusP]

I guess you sadly don't know how the fps were limited before the drops happened? (cpu, gpu, limiter, vsync)
To determine what might've changed it would be really good to know if we have to look for cpu things or gpu things.
If you didn't change anything in ac or the driver settings I'd say fullscreen optimizations etc might've been activated by a windows update.

Otherwise I sadly have no clue...

It would still be useful to know what's the limiting factor is right now so please grab a hardware monitoring tool (msi afterburner, openhardwaremonitor etc) and tell us your graphics card usage. If you don't limit your fps with a limiter or vsync it's either 99% graphics card usage or it's your cpu.
That way we can investigate further

 

[Billy Pilgrim]

I guess you sadly don't know how the fps were limited before the drops happened? (cpu, gpu, limiter, vsync)
To determine what might've changed it would be really good to know if we have to look for cpu things or gpu things.
If you didn't change anything in ac or the driver settings I'd say fullscreen optimizations etc might've been activated by a windows update.

Otherwise I sadly have no clue...

It would still be useful to know what's the limiting factor is right now so please grab a hardware monitoring tool (msi afterburner, openhardwaremonitor etc) and tell us your graphics card usage. If you don't limit your fps with a limiter or vsync it's either 99% graphics card usage or it's your cpu.
That way we can investigate further

Thanks for your tips.

I used MSI Afterburner to record CPU core usage and GPU usage.

The CPU cores are running most of the time at around 50 to 60%, one or two of them a little higher: 60 to 70% and one peak at 97% (for one core) at the beginning of the race (grid of 16) but just for a moment.

GPU usage is at running at 55 to 80%. Its max is at 83%. The GPU graphs for Core clock, Memory Clock and for Memory usage all max out at 100% and the graphs run flat at 100% for the whole race.

RAM usage is not maxxed out at all.

 

[Kek700]

Just out of interest.
what FPS are we talking about. ( on start line )
What circuit. ?
Is it 1080p triples. ?
Especially interested with respect to 1080ti
I have some information on this and I am always
interested in comparable situations.

 

[RasmusP]

This is clearly a CPU limitation. You should check if something is running in the background, Windows changed some settings (game mode, fullscreen optimizations etc) or if reflections or something got changed.
Apart from that I'm sadly clueless

 

[Billy Pilgrim]

Just out of interest.
what FPS are we talking about. ( on start line )
What circuit. ?
Is it 1080p triples. ?
Especially interested with respect to 1080ti
I have some information on this and I am always
interested in comparable situations.

Ok
It's the fps of the first lap or most of the first lap.
Kunos tracks. I mostly use Brands Hatch to check fps.
1080p triples.
What info do you have?

 

[Billy Pilgrim]

This is clearly a CPU limitation. You should check if something is running in the background, Windows changed some settings (game mode, fullscreen optimizations etc) or if reflections or something got changed.
Apart from that I'm sadly clueless

Thanks for the tips.
I'll check whether game mode is on.
Where would I look for fullscreen optimisations? Windows? Nvidia control panel? Content Manager?
Why do you say it's cpu limited? The cpu cores were running a long way below 100%

 

[RasmusP]

Ok
It's the fps of the first lap or most of the first lap.
Kunos tracks. I mostly use Brands Hatch to check fps.
1080p triples.
What info do you have?

I think it was more about what numbers of fps we're talking about. Drops to 40 or just from 100 to 60 etc

 

[RasmusP]

Thanks for the tips.
I'll check whether game mode is on.
Where would I look for fullscreen optimisations? Windows? Nvidia control panel? Content Manager?
Why do you say it's cpu limited? The cpu cores were running a long way below 100%

Regarding fullscreen optimisations I sadly don't know for sure. I'm on Win 7 still...
It should be rightclick on the .exe somewhere...

About "single thread limit", read my post here:
https://www.racedepartment.com/threads/cpu-and-gpu-not-fully-utilized-why.162601/#post-2880089

 

[Billy Pilgrim]

I think it was more about what numbers of fps we're talking about. Drops to 40 or just from 100 to 60 etc

I'm getting 56 to 75, and was getting 75 to 95 before

 

[Denis Betty]

Rasmus, are you saying that we should disable full screen optimisations?

 

[RasmusP]

Rasmus, are you saying that we should disable full screen optimisations?

I'm saying @Martin Fiala knows some stuff about Win 10 interfering with games while I only read his post but have no first hand experience
It's just guessing into the wind why Billy has increased CPU usage out of the blue...

btw what happens when you alt+enter out of the game and alt+enter back to fullscreen? With my new gsync monitor I get around 40-50 fps before I do this. That is a really strange one but I can live with it. Only have to do it once when entering the track...
Nothing makes me wonder nowadays lol

 

[Billy Pilgrim]

Regarding fullscreen optimisations I sadly don't know for sure. I'm on Win 7 still...
It should be rightclick on the .exe somewhere...

About "single thread limit", read my post here:
https://www.racedepartment.com/threads/cpu-and-gpu-not-fully-utilized-why.162601/#post-2880089

I liked the nail and hammers analogy.
So if it's cpu limited, I'll get better performance if I overclock more? (which I can)

 

[Billy Pilgrim]

btw what happens when you alt+enter out of the game and alt+enter back to fullscreen?

Are you suggesting I should do this (alt plus enter)? You do that once you're actually in a race/in acs.exe?

 

[RasmusP]

I liked the nail and hammers analogy.
So if it's cpu limited, I'll get better performance if I overclock more? (which I can)

Yes, absolutely. I won't do it though until you've figured out what the heck went nuts with your Assetto Corsa

Btw, the more cores, the higher the single thread performance but also the earlier in "absolute cpu load" the limit will come.
While an i3 will be maxed out with all 4 cores at 100% most of the times, a Ryzen 2700x will run at more or less the same fps in a game like Assetto Corsa. But the 2700x will only be at 30% cpu load. Still limited but also room for streaming, music etc.

 

[RasmusP]

Are you suggesting I should do this (alt plus enter)? You do that once you're actually in a race/in acs.exe?

Yep I do. It's really strange... Gsync is set to fullscreen only so I enter the track and gsync is active but I only have around 40 fps. I tab out of the game, gsync goes off but the fps instantly go up to normal numbers (limited to 75 for me). I then have to hit alt+enter again to make AC switch into exclusive fullscreen again so gsync gets activated again.
Just test this to make sure it's not the same!

 

[Billy Pilgrim]

Yep I do. It's really strange... Gsync is set to fullscreen only so I enter the track and gsync is active but I only have around 40 fps. I tab out of the game, gsync goes off but the fps instantly go up to normal numbers (limited to 75 for me). I then have to hit alt+enter again to make AC switch into exclusive fullscreen again so gsync gets activated again.
Just test this to make sure it's not the same!

I'll test it tomorrow

 

[Case_]

I obviously can't speak for someone else's system, but in my experience, fullscreen optimizations on/off (they're enabled by default since last year or so I believe) do not have any real impact on performance and should not be causing 25 % framerate loss. Especially not on 1080Ti IMO. It's more about microstuttering and/or input lag, as well as (sometimes) compatibility with certain utilites, like ReShade. And - again, at least in my experience - it's less and less necessary to even bother messing with fullscreen optimizations.

If that framerate loss happened after Windows update, my guess would be there was some driver replaced with an old/different version (Windows likes to do that sometimes). I've also had an interesting thing happen a few times in the past where the nVidia drivers (or possibly Afterburner) somehow got wrong settings and basically downclocked my GPU, so everything looked OK, but the performance went down a third or even more. If I remember correctly, I had to basically reset the clock settings and make new profiles to solve that.

Also, I did have some weird issues and performance problems with the latest 41x.xx drivers on my 970. 417.22 seem fine, but going to the latest ones (417.35 I believe) I lose good 10-15 fps in AC:Odyssey for example, and the previous drivers also had some issues for me. But again, that's on 970 and a fairly old system in general.

 

[Billy Pilgrim]

Thanks for your various help and advice.

I seem to have fixed it. Took ages!

I rolled back a couple of recent Windows updates. That gave me some frames back.

I updated Reshade to its latest version. That gave me frames back.

I re-overclocked the CPU and that gave me frames back. (I'm wondering if I had somehow turned off the overclock for this inadvertently - but I don't know. i'm using Asus 4-way optimisation forthis overclock - wow it's simple!)

The Windows updates I uninstalled were security updates though. Don't know if I'm taking risks by uninstalling them.

 

[Case_]

(I am really not a fan of not installing or rolling back updates to "solve" problems, especially since those problems are rarely *actually* caused by those updates directly and just get blame for various only marginally related issues, and it is IMO in everyone's best interest to have the OS up to date, but...that's up to everyone to decide for themselves, I guess, as long as I'm not responsible for their PCs )