Looking for help in getting to run smooth

[mteam]

Hi I've only recently got ACC and finding it difficult to get it running smooth
I5 9600k 16GB 3600mhz ram RTX2080 installed on SSD 1080p my monitor is freesync but not on the nvidia list
I've been testing @ barcelona tonight practice on my own between 150-180fps
Race 24 cars 100-130fps
Which I think should run quite well
I'm not getting big stutters but just doesnt seem smooth
I tried limiting frames to 60 and vsync it was worse ?
My monitor can go up to 75hz should I push it up to that?

AC runs super smooth so I wonder if it doesnt have enough grunt for AAC?

Thanks

 

[RasmusP]

What Hz is your monitor?

Seems like gsync compatible isn't working. Without any syncing, I can see stuttering until I use a 240 Hz monitor.

Vsync only works if your fps are higher than your Hz. It automatically limits your fps to your Hz value then.
Also 1-3 frames get "buffered", so you get input lag.

If you limit the fps below the Hz while using vsync, the frames will get displayed multiple times.
60 fps with 100 Hz means one frame every 16.67ms (1000ms / 60).
While your monitor refreshes with 10ms.
So frame 1 gets displayed with monitor refresh 1.
But when the monitor needs frame 2, the fps take another 6.67ms to get sent to the monitor.
So the monitor will display frame 1 again.

Then after 20ms, the next frame will be buffered since 3.33ms and will get displayed in sync with the third monitor refresh.

This continues until the gap between the Hz and the fps becomes 16.67ms and you'll get one frame displayed only for 1 refresh instead of 2.

So you're not running 60 fps.
You're running 50 fps with some short moments with 100 fps.
And this is very visible with stuttering!


I guess AC is running with vsync and higher fps than your Hz, so it works like it should.

For acc, you have 2 possibilities:
- Get gsync compatible mode working

- set a lower Hz in the windows/nvidia settings (they do the same) and use vsync

But don't use a limiter! Let vsync limit the fps.

When this is running, there's another trick:
With riva tuner (rtss), you can limit the fps in decimals. Like 59.95 fps.

If you have a 60 Hz Monitor and limit the fps to 59.97, there will be one frame displayed 2x every now and then, but you won't see it.
But somehow this keeps the frame buffers clean and massively reduces the input lag from vsync.

To find your real Hz value, use the "vsynctester":

Web browser "VSYNC synchronization", display Hz, and input lag tester

My 120 Hz phone display shows 118.15 Hz

 

[mteam]

Hi Rasmus
Its been a long time since we last spoke I bet you were helping me with an issue last time

I had my monitor running at 60hz I can up it to 75hz in windows display not sure what it does tbh

I dont run vsynch on AC and it seems to run at about the same fps as ACC

Thanks

 

[RasmusP]

Mhh, if you don't use any syncing with both sims and they are running at about the same fps, they should also look the same.

If they don't, I sadly have no idea why that would be.
But using vsync should make things completely smooth and lock the fps to 60.
Maybe try vsync again but without any fps limiting (or set to something higher than 60, like 70+).

If the fps don't lock to 60, there's an issue.

 

[eco2006]

I have a similar problem with my rig, 60hz monitor without freesync or gsync. When i use v-sync the frametimes are pretty unconsistent and it doesn't feel good. I tried every method i know and found, but couldn't get decent results until i tried "scanline sync" in rtss. Maybe try and give that a go.

 

[RasmusP]

When i use v-sync the frametimes are pretty unconsistent and it doesn't feel good.

How did you check the frame times? With vsync and no limiter, the frame times fluctuate a little bit, yeah.
But the image on the monitor should be absolutely super smooth. The only downsides are:
If you even have a single frame time longer than your refresh rate, that frame will get displayed 2x and you'll see a big micro stutter.
And the other downside is the input lag.

So what do you mean with "doesn't feel good"? Just the input lag or did you see stutters?

"scanline sync" in rtss. Maybe try and give that a go.

Yeah it's brilliant indeed! Just a bit more complicated than using vsync. But if I wouldn't have gsync, I'd probably use that!

 

[mteam]

Just an update turning on vsync without fps limiting seems to have fixed it

Thanks All