Where are my frames going & how do I get them back?

MrBraindown

Premium
Howdy, I posted this on discord last night, but it probably wasn't the correct platform to host my question.

I was playing AC in VR last night, my first race ran fine, smooth as butter but during the second race my frame rate plummeted. I changed a few things, but nothing seemed to improve so I rebooted the PC. The first race was fine, but again during the second race the frames dropped massively. I normally get 50-60 fps, but during the second race it went to 15-20. I've not changed anything, so I'm a bit confused as to why this is suddenly happening.

This morning I tried it without VR, first race 85 fps, second race 35 fps (same track, same cars, same environmental settings) so what is going on? Its almost as if its caching something which throttles the fps and rebooting seems to clear it.

Has anyone got any tips on what I need run through to troubleshoot the issue?
 
It might be worth having a look @ your recording replay quality settings & the auto save options... It might also help to provide some system specs, duration of the races, opponents - AI or human... including all apps in use.

If you're 'normally' getting 50-60 fps in VR, it sounds like your system is already struggling.
 
Many thanks for the reply, it's much appreciated.

I'm running an AMD 2600x CPU and RTX2070. I run Crew Chief, SimHub and ReShade in the background, athough I've turned all those off and it doesn't make a difference. I've also rolled back the last Windows update and Nvidia driver update and that didn't change anything.

Even rebooting my PC now doesn't seem to improve performance. I've attached some screenshots of the race set up, plus the graphical settings with the FPS I'm getting. Although strangely, I can crank up all the settings to maximum levels and the FPS doesn't change at all.

For reference, I get 80 - 90 fps on ACC (single screen)

I've checked the replay stuff, that's all normal and it's not something I've changed recently either.

I'm really stumped, as I would normally get at least 80 fps with these settings so any advice would be greatly received. (These screen shots are taken when running on single screen not VR)


content manager settings1.png
content manager settings2.png
 
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I don't use Content Manager :( . At a quick glance though I can see that there are few settings that are going to be challenging for your cpu - MSAA @ 8, World detail @ Very High... I have a R5 3600X & 1080ti gpu (runs around 35-40% in game) & my settings are lot lower:
AC VR Display settings.jpg


My performance tends to tank when I'm in over-sized grids (over 24 cars), & seems to be cpu related. Maybe try testing again with just Kunos content & fewer cars?


 
Thanks for this info, really useful, I'll fiddle with the settings some more.

It's just strange that I was hitting 70-80 no problem at all for as long as I can remember, only for it to now start tanking. Other games are not affected, just AC - as I mentioned ACC runs around 80 with high settings, 29 cars on grid etc.

I might just go for a fresh install of AC and CM and see if that makes a difference.
 
For some reason I have been having threading problems.
It seems to change once in awhile but what really made a difference was optimizations/CPU/GPU in CM. Check off all the boxes (a dozen or so) except mergemeshes. It can cause problems with some tracks.

But even with this I notice frame rates drop sometimes, just not as bad. I still think threading is an issue with my system?
 
I've completely purged AC from my PC and currently reinstalling everything because nothing I seem to do makes any difference.

See example screenshots below, these were taken before I uninstalled:

42.9 fps with everything off or on minimum:
content manager settings 3.png


68.6 fps with everything on:
content manager settings 4.png


Same track, same number of cars, I literally just reran the same race once the first had finished. Something weird is going on. All this whilst ACC holds a steady 85 with all the settings on high and above.

I'll report back after my reinstallation!
 
Hmmmm..... Install finished and just re-ran the same race. The only difference being not having Sol installed yet.

View attachment 382280

Are you still getting a frame drop in the second race?

It is odd that you're getting a better framerate with the settings turned up. Do you have any anti-malware/virus software running in the background? Are any of your cpu threads getting maxed out?

I'm not sure that it is a long term solution, but I run/manage the threads (4 in total) that AC uses through a program called Process Lasso - basically avoiding the first few threads that windows is likely to use.
AC process lasso.jpg


I don't use Process Lasso for any other game - Windows is far better at it.
 
Not had a chance to test yet, I had to come off the PC because I had been on it “all bloody day” apparently (I really haven’t but I daren’t argue) I’ll jump on once the kids are in bed. If I get the same issue I’ll take a look at Process Lasso - thanks for the heads up.
 
Are you still getting a frame drop in the second race?

It is odd that you're getting a better framerate with the settings turned up. Do you have any anti-malware/virus software running in the background? Are any of your cpu threads getting maxed out?

I'm not sure that it is a long term solution, but I run/manage the threads (4 in total) that AC uses through a program called Process Lasso - basically avoiding the first few threads that windows is likely to use.
View attachment 382282

I don't use Process Lasso for any other game - Windows is far better at it.
Thanks for this!
I have been fighting this problem for years with AC but wasn't a 100% sure it was a threading problem until now. I know the optimization in CM helped a little but will give this a try.
Which version do you use? Free or paid?
 
Are you still getting a frame drop in the second race?

It is odd that you're getting a better framerate with the settings turned up. Do you have any anti-malware/virus software running in the background? Are any of your cpu threads getting maxed out?

I'm not sure that it is a long term solution, but I run/manage the threads (4 in total) that AC uses through a program called Process Lasso - basically avoiding the first few threads that windows is likely to use.
View attachment 382282

I don't use Process Lasso for any other game - Windows is far better at it.
Can this threading bottle neck interfere with physics, as in rubber on the road/FFB as well?
 
Back down to 45 FPS this evening, seconds after completing a race at 95 FPS. What is going on? :( Turned off the PC in a massive huff!

Did you have a look @ the video replay/record settings in AC? Do you have gsync enabled? Have you worked your way through the threads here & over at Kunos to see if someone else is having the same problem? It might also be worth trying MSI Afterburner - displaying all cpu threads in both races.
 
Strangely, I've run a couple of races today (in between my kids home schooling lessons ;)) and it's held steady around 75 fps. I've turned all the replay stuff off and fiddled with a few other options. I've googled and searched forums for alternative answers - some people do experience similar symptoms, but their solutions don't make a difference to me. Good shout on Afterburner, I'll fire that up and check
 
I am having a very very similar problem. And I also spent "all bloody day" on my PC trying to fix it.

So until last night I would be happily getting 100 fps with my benchmark (16 GT3 AI at Brands with me at back of grid). Then last night I started getting 65 to 75 fps in most, but not all, race sessions. Then sometimes I go into a race (my benchmark) and get 100fps. And this seems to be happening randomly.

Ten minutes ago I had a race at Brands at 100 fps, then I exited and fired it up again and I'm getting 70fps.

I've checked with MSI Afterburner: my temps are all good.

I have a 1080ti, triples, i7 4770k OC @4.4.

I have a couple of clues here:
  • when the fps is bad, the race takes much longer to load. I even know if the problem will be there or not before the race has loaded by how long the loading is taking.
  • when the fps are good, (at 100fps), using the Task Manager performances tab I see that the GPU is running at 95 to 99% and when I'm getting 70 fps my GPU is running at 55 to 73%,
I have spent about eight hours fiddling about with things over the last 24 hours and I just can't solve it.

Here's a thread I posted on this (the post started two years ago when I once had the same problem) and I continued the thread today.

Any help would be much appreciated.
 
I've noticed the 'long to load' issue as well, so it does sound like a similar issue to mine.

I really don't know what is causing it, but it reminds me of an issue I had years and years ago (probs about 30!) with a donkey kong style game. The first time you fired it up it played smoothly, but if you died and started a new life it wouldn't run as quickly. Then if you died and started another new life it would be grindingly slow.

After some investigation it appeared that the computer loaded up a whole new game from scratch each time you played, so you could end up with about 5 instances of the game, all running at once.

I know this isn't whats happening here, but this issue reminds me of that exact same thing, especially when rebooting the sytem seems to (temporarily) clear it. Not useful for you guys to know this at all, but I felt the need to share. Cleansing. :D

I'll have a look through your thread, maybe there's something in there that could help me. Thanks.
 
I have noticed today, over the 20 or so reboots, that the chance of my fps being ok was better after a reboot - but that's all, just an improved chance.

I have no clue now what I should do to try and fix it, I've done all the things to do now, to my knowledge.
 
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