Stutter Question

[Zimmerbz 153]

I notice that in the A320 FBW Mod, I get stuttering in my lower left view when in the captain view.  Looking forward and panning the cockpit is smooth, but in my left "peripheral" left window I almost get stutters all of the time.  Is there a setting that I can reduce that would potentially help?  Most of my settings right now are high/ultra so if there is one area that would cause this, i'd like to investigate.  My frames are right around 30 when I get this as well.   Thanks!

Edited January 12, 2021 by Zimmerbz

[Zimmerbz 153]

Also, I might add that my render is 80 and all of the other sliders are 100.  The stutters are just noticeable enough to where it is annoying but the sim is still able to fly. 

[Glenn Fitzpatrick 3,798]

It would be a good idea to turn on the FPS counter and see if the game is GPU limited or main thread limited when the stutter occurs.

 

That will give you more idea what to tweak.

[Zimmerbz 153]

9 minutes ago, Glenn Fitzpatrick said:

It would be a good idea to turn on the FPS counter and see if the game is GPU limited or main thread limited when the stutter occurs.

 

That will give you more idea what to tweak.

The FPS counter in Dev mode?  What should I be looking for in the counter to understand what needs to be tweaked?  I'm not very technical! 

[Glenn Fitzpatrick 3,798]

The very top of the counter is the FPS

The next line under that tells you what is currently limiting the FPS. it will usually say "limited by GPU" or "Limited by Main Thread" (CPU) or occasionally "Limited by Render Thread" .  on a well balanced system this will flip between them randomly multiple times a second.

On an unbalanced system either the GPU or CPU will almost go to sleep waiting for the other one to finish and then struggle to catch up.  You can set various things to "high performance" to stop stuff going to sleep but you are still better off with a balanced setup that hammers CPU and GPU equally.

This gives a hint as to whether you need to tweak settings that rely on GPU or instead change things that hammer the CPU (like LOD) in order to balance it out.

 

Edited January 12, 2021 by Glenn Fitzpatrick

[Zimmerbz 153]

3 hours ago, Glenn Fitzpatrick said:

The very top of the counter is the FPS

The next line under that tells you what is currently limiting the FPS. it will usually say "limited by GPU" or "Limited by Main Thread" (CPU) or occasionally "Limited by Render Thread" .  on a well balanced system this will flip between them randomly multiple times a second.

On an unbalanced sytem either the GPU or CPU will almost go to sleep waiting for the other one to finish and then struggle to catch up.  You can set various things to "high performance" to stop stuff going to sleep but you are still better off with a balanced setup that hammers CPU and GPU equally.

This gives a hint as to whether you need to tweak settings that rely on GPU or instead change things that hammer the CPU (like LOD) in order to balance it out.

 

Thanks.  I am not  sure what I am looking at but the numbers show as follows on a flight from LGA-YUL at night

FPS in the top in the Red (30)

"Main thread" was 20 ish

"rdr Thread" was around 5

Manipulators - 10-15

CoherentGTDraw - 10-15

GPU - 20 

[Zimmerbz 153]

Do these numbers make sense taken from the FPS counter in Dev mode?  I can try to report something else if this is not what i was supposed to show.  

[RobJC 2,069]

There is a line that will either say "Limited by GPU" or "Limited by Main Thread". It will flicker sometimes but when you are in the air one or the other should do the predominate message you get. If you are getting stutters and not just low FPS then you will probably see Limited By Main Thread often. The three states I have observed are:

1. "Limited by GPU" most of the time.

2. "Limited by Main Thread" most of the time.

3. Flickering between the two constantly. 

To reduce stutters you need the highest FPS you can get while still seeing "Limited by GPU" most of the time.

When the CPU becomes the bottleneck, the stutters are going to show up.  

So what you want to do is increase some of your graphics settings to push your system into being GPU limited, while still maintaining a good frame rate. When the GPU starts waiting for the CPU you will have stutters. You need the CPU to be waiting for the GPU. 

 

[Zimmerbz 153]

53 minutes ago, RobJC said:

There is a line that will either say "Limited by GPU" or "Limited by Main Thread". It will flicker sometimes but when you are in the air one or the other should do the predominate message you get. If you are getting stutters and not just low FPS then you will probably see Limited By Main Thread often. The three states I have observed are:

1. "Limited by GPU" most of the time.

2. "Limited by Main Thread" most of the time.

3. Flickering between the two constantly. 

To reduce stutters you need the highest FPS you can get while still seeing "Limited by GPU" most of the time.

When the CPU becomes the bottleneck, the stutters are going to show up.  

So what you want to do is increase some of your graphics settings to push your system into being GPU limited, while still maintaining a good frame rate. When the GPU starts waiting for the CPU you will have stutters. You need the CPU to be waiting for the GPU. 

 

Interesting... what do you suggest i increase to be more GPU limited?  These are my current settings:

 

 

Edited January 13, 2021 by Zimmerbz

[MrFuzzy 2,117]

5 minutes ago, Zimmerbz said:

Interesting... what do you suggest i increase to be more GPU limited?  These are my current settings:

 

 

Increase render scaling to 100, set volumetric clouds on Ultra and water waves on high. Also ambient occlusion affects the GPU only and can be increased to Ultra.

 

[bobcat999 8,438]

I have found from experience myself that what RobJC and MrFuzzy have said above makes perfect sense.  Although what they are saying can sometimes seem counter-intuitive, it definitely does work.

I lock at 30 fps now, with settings raised until 'limited by GPU' shows, and the only stutters/pauses I get are very occasional and due to scenery loading from disk, or internet data stalling out on me.

The only thing I would caution against is turning up ambient occlusion, as this can cause artefacts / glow effects around the edges of objects.  It may be dependent on what video card you have. 
Mine is best on low - it looks to dark and shadowy on higher settings anyway (just my opinion).

The best way to drive into the 'limited by GPU' territory is to gradually turn up the render scaling, and enjoy the extra quality as you go! 

Edited January 13, 2021 by bobcat999

[Zimmerbz 153]

Thanks!  I'll give these suggestions a try and report back!

[Zimmerbz 153]

When I did this, it would appear as though my frames dropped from about 30 to 25 and it said underneath the FPS, "limited by GPU".  I took off from LVFR MIA and i still got some stuttering but it did feel a bit smoother.  I changed the settings to ultra per the request that seemed good.  However, when I tried to lock the FPS at 30, my FPS dropped to the teens.  

[bobcat999 8,438]

Ok.  That shouldn't happen.  How are you locking at 30?  If it is in the sim, it is buggy and tends to halve the displayed frame rate, e.g 30 will be 15.

Riva Tuner (RTSS) is the best way for your 2070 super.  It will be faultless for that, then pull back your graphics settings until you can hold 30 fps, and it will be a smooth experience.  It will be a fine balancing point but it should be possible with your system.

Edited January 13, 2021 by bobcat999

[Ianrivaldosmith 5,317]

1 hour ago, Zimmerbz said:

When I did this, it would appear as though my frames dropped from about 30 to 25 and it said underneath the FPS, "limited by GPU".  I took off from LVFR MIA and i still got some stuttering but it did feel a bit smoother.  I changed the settings to ultra per the request that seemed good.  However, when I tried to lock the FPS at 30, my FPS dropped to the teens.  

With ultra, drop your LOD to 100 from 200, that should eliminate any remaining stutters you have when gpu limited.