1.33 Microstuttering/ twitching

[janis22]

Hi there,
I have only recently obtained the wonderful ixeg. I have noticed some micro stuttering.
FPS is at around 50-60. Experimental flight model is on and 2 flight models per frame.
(xprealistic is off)
Here is a video of it.
https://youtu.be/qZp3pzCz7pI

Edit: I am on xplane 11.41and on Gizmo64 18.02.27.0200

Edited August 31, 2020 by janis22

[Litjan]

Hi Janis,

Try the new Gizmo Beta and see if that works better for you?

For general X-Plane stuttering you can also try the 11.50 beta versions of X-Plane (Vulkan) - this will also help with stuttering.

Cheers, Jan

 

Edited August 31, 2020 by Litjan

[janis22]

Hi Jan,
thanks for the super quick reply.
Gizmo Beta indeed improved it. But also turning G-Sync on somehow helped. Strange though because this never was an issue in other aircraft.

Cheers
Janis

[Cameron]

16 minutes ago, janis22 said:

Hi Jan,
thanks for the super quick reply.
Gizmo Beta indeed improved it. But also turning G-Sync on somehow helped. Strange though because this never was an issue in other aircraft.

Cheers
Janis

People need to stop doing the "other aircraft" comparison. There is no apples to apples here.

[Litjan]

8 hours ago, janis22 said:

Strange though because this never was an issue in other aircraft.

Cameron is right, this can be misleading. Different aircraft are providing different methods and depth of simulation and that will show in the load on the computer hardware (i.e. framerate).

We are constantly striving to improve performance and Ben Russel, the developer of Gizmo, has made great strides in this - plus we as the developer of the 737 are learning more tricks all the time as well.

I am happy that the beta Gizmo brought some improvement for you. Especially with the increased "smoothness" of X-Plane (11.50 Vulkan) it has become even more important to us to not add unnecessary periodic load on the process and we still have some ideas in the pipeline.

Cheers, Jan

 

[Torbinator]

Well, I'm assuming @janis22 might have been simply trying to provide confidence that the issue is specific to IXEG/Gizmo. I know I've shared bug & performance reports with developers here and other products in a similar fashion.

Here is an example that I never got around to sharing here or with Laminar, but this post reminded me of the situation: I noticed around XP 11.32(?) that a change in engine indicator behavior in the 733 became apparent. Prior to XP 11.32, I was able to watch the oil pressure rise while waiting for the N2 to rise to 25%, as per described and instructed in FCOMs. IIRC, we are supposed to avoid flipping that fuel lever to idle if we don't see a rise in oil pressure before reaching 25% N2. However, as of XP 11.32 and beyond I saw the oil pressure stay at 0, then suddenly "kick in" noticeably above 20% N2, which seemed kind of late based on what I read.

At first I wondered if it was IXEG's engine simulation was no longer compatible with a change made by Laminar, but then I saw it on the FlyJSim 732 and Rotate Sim's MD-88 aircraft. Given that it occurred with several planes and not just IXEG, some of us laymen might begin to ponder whether Laminar's tweak was faulty, and therefore not bother you folks by sharing that here. Although, one could cautiously suspect that all three aircraft devs planes are now faulty because Laminar refined their engine modelling and the devs needed to adjust.

Anyway, I think the observation of whether or not it's happening in other aircraft can be valuable in many end-user's minds given that many of us lack the coding insight you guys deal with when creating these fine digital replicas. However if there's a better way to convey whether or not we see it in other aircraft, please share.

Thanks!

Edited September 1, 2020 by Torbinator

[Litjan]

6 hours ago, Torbinator said:

However if there's a better way to convey whether or not we see it in other aircraft, please share.

You are probably right with your observation. It is all to human for us producers and purveyors of a product to instinctively react defensive - especially when the customer pulls the "other products..." card . It strikes a very sensitve nerve in us competitive human herd animals!

It takes the patience of a Jedi to not raise your heartbeat a bit when someone says "I have this problem with your aicraft, and all the other aircraft don´t have it!". It is akin to saying "how come you guys can´t do as well as the other guys?"

Nevertheless it it always correct to point out a problem that you have with a product - and sure, if we don´t acknowledge or even deny a problem - reinforce the point by making a comparison with another product.

Cheers, Jan

[Cameron]

I do not find comparisons to other products any bit useful or meaningful. Programming methods, APIs, and the way in which things overall interact with the sim are different product to product. We don't have source to other developers' projects, and thus, it's just a baseless, honestly useless comparison that conveys a pure lack of knowledge on the customers' part that this is not apples to apples.

That's the honest, blunt, to the point way of saying it. I'm not trying to be rude, just real.

My honest pet peeve in the tech support side is literally the "no other aircraft" card. To me, it has nothing to do about competitive nature at all.

[sho69607]

I am also having some issues with stuttering as well. Tried some of the solutions listed above, but I haven't had much success. GSync is on and I removed XPrealistic but I didn't see any performance difference when it was installed to begin with. I also tried messing around with the garbage collector feature and that helped somewhat, but the stutters are still quite prevalent. Should I try rolling back to 11.40+ instead of Vulkan? I understand Vulkan is supposed to help with the stuttering, but it is also still in beta so I am not sure how much stability I can expect from it or not. I tried both versions of Gizmo, but for me personally the performance was the same with both versions.

[Litjan]

There is one more thing you can try - switch off the WXR SYSTEM switch (found between the two CDUs).

Some meshes have a very high count of elevation points - our weather and terrain radar scans these elevation points at regular intervals and we had reports of those causing "code slowdown" every few seconds.

The other question is: What kind of framerate are you getting with OpenGL and with 11.50?

Cheers, Jan

 

[sho69607]

5 hours ago, Litjan said:

There is one more thing you can try - switch off the WXR SYSTEM switch (found between the two CDUs).

Some meshes have a very high count of elevation points - our weather and terrain radar scans these elevation points at regular intervals and we had reports of those causing "code slowdown" every few seconds.

The other question is: What kind of framerate are you getting with OpenGL and with 11.50?

Cheers, Jan

 

Ok I'll try that. Frames with 11.5 have been anywhere from 40-50FPS. I haven't used the OpenGL version in awhile, but I recall the FPS being closer to 30 when I was using it. Frames are really good I just need to figure out the stuttering issue that is happening in 11.5.

[mizra108]

Hi there, if I may squeeze into this conversation too as I just recently started experiencing the micro stutters/twitching, all of a sudden and for no known reason as I have not changed xp versions, nor upgraded the aircraft prior to getting the stutters which were not there before on prior flights. I am running 11.50RC3 with vulkan enabled and 1.33 on the aircraft. Regardless of stuttering, FPS is always pegged at 60 as I have V-sync enabled. I tried uninstalling and reinstalling the aircraft but that did not change anything. It seems to be IXEG related as I swaped aircraft and stutters went away. I'm also using Gizmo beta.

Oh and I did disable the wx switch but that did not change the stuttering.

Any suggestions?

Edited September 6, 2020 by mizra108

[Litjan]

There is a lot of calculation going on behind the scenes when you run the IXEG 737 - and with the base simulation becoming faster and more smooth, this calculation (naturally causing lag) is becoming a bit more appearant. In the past the emphasis was on causing "less total load" on the system - so you would run some operations only every 5 seconds, instead of "every flight loop". This would allow to keep the general framerate up, and small dips did not "stick out" very much in an already fairly slow and stuttery base simulation.

Now with Vulkan allowing faster and really smooth framerates, calculation delays cause these observable stutters.

Ben is continuously working on evening out the load placed by these computations by improving Gizmo, and we will also have to look into our code and decided if we need to "spread out" things more to get a more smooth load - at the cost of diminishing framerate.

If you look at other add-ons of comparable complexity (I am not talking a small Cessna or TBM here) you may also see either a more choppy rendering or a fairly diminished framerate compared to "default" aircraft.

We strive to make things as smooth and fast as possible - but naturally we need time to adapt to the post-OpenGL situation.

Cheers, Jan

 

[sho69607]

17 hours ago, Litjan said:

There is a lot of calculation going on behind the scenes when you run the IXEG 737 - and with the base simulation becoming faster and more smooth, this calculation (naturally causing lag) is becoming a bit more appearant. In the past the emphasis was on causing "less total load" on the system - so you would run some operations only every 5 seconds, instead of "every flight loop". This would allow to keep the general framerate up, and small dips did not "stick out" very much in an already fairly slow and stuttery base simulation.

Now with Vulkan allowing faster and really smooth framerates, calculation delays cause these observable stutters.

Ben is continuously working on evening out the load placed by these computations by improving Gizmo, and we will also have to look into our code and decided if we need to "spread out" things more to get a more smooth load - at the cost of diminishing framerate.

If you look at other add-ons of comparable complexity (I am not talking a small Cessna or TBM here) you may also see either a more choppy rendering or a fairly diminished framerate compared to "default" aircraft.

We strive to make things as smooth and fast as possible - but naturally we need time to adapt to the post-OpenGL situation.

Cheers, Jan

 

Thanks for explaining it. Is there a reason why the stutters are more noticeable on the ground? Once I takeoff I don't really notice it. Maybe less detail rendering or something?

[mizra108]

2 hours ago, sho69607 said:

Thanks for explaining it. Is there a reason why the stutters are more noticeable on the ground? Once I takeoff I don't really notice it. Maybe less detail rendering or something?

I have found they are still there but yes, they show less. Perhaps its just a visual just as in real life where you dont percieve the movement across in the air quite as fast as when you are on ground

Edited September 8, 2020 by mizra108

[Litjan]

You can just see it more readily because the ground "rushing by" covers more appearant angle when you are close. If you are tracking a taxiway light with your eyes while you pass it taxiing at 30kts it you have to turn your eyes like 50 degrees in one second. If you watch the same taxiway light while flying by at 5000 feet you need to turn your eyes 0.5 degrees per second. So if you have a "stutter", the "jump" of the light is bigger when you are passing close by.

Cheers, Jan

 

[Iain]

No stutters here and setup is the same as pre patch....although I have a couple of other points but I need to test them before posting my results (keyboard shortcuts not working anymore).

PS  The views were reset again in this patch!  But I had my old prefs file ready! 

[Litjan]

10 hours ago, Iain said:

keyboard shortcuts not working

A lot of shortcut commands were changed/corrected/added - maybe that is causing problems for old assignments?

Cheers, Jan

 

[Iain]

I'm sure it is, will correct mine soon.

[Iain]

Sorted, it was because I used my old prefs file as I didn't want to setup the views again!  Fresh install and the keys are workings, along with many other options!