GSX Causing Stuttering Randomly

[dogfighter2111]

Hi,

I have noticed an issue over the past few months, wherby MSFS will start to stutter randomly whilst using GSX. GSX is up to date. I have noticed that there seems to be a higer rate of this happening during the fuel truck animation, but not exclusively.

There are no FPS drops or CPU spikes. The stuttering happens only when moving the camera/eye view, not when at a fixed point. Or you can see the vehicles stuttering as the move.

I have tried restarting GSX and Coutl to see if a reset fixed it, but no. Only restarting MSFS resolves the issue. Wondering if anyone else has had this or if there is a clue as to what is causing it?

GPU usage is normal with average FPS of around 70-90, CPU usage between 15-45% depending on activity. Nothing abnormal except for the visual stutter.

Thanks 

[virtuali]

Here's a video made by an independent reviewer who tried to assess, of the most popular add-ons out there, which one contributes the most to fps drop:

https://youtu.be/XVjThxh4fRk?si=Q7CAduSrGF2EeWKF&t=378

Not only GSX impact on fps was negligible, but it even IMPROVED the stuttering, with less CPU spikes.

There are no FPS drops or CPU spikes. The stuttering happens only when moving the camera/eye view, not when at a fixed point.

This is MSFS itself which is trying to save memory by dropping and reloading textures which are going in and out of view. This handling has a cost, because dropping and reloading textures will cause having textures crossing again the RAM-VRAM barrier (the PCI bus), which will stall everything. Of course, this is valid for all objects in view, not just GSX vehicles, but you might not see this handling in effect until enough of VRAM is taken. But clearly, VRAM allocation is caused by everything summed together so, if you are on a default airport on a default airplane with only GSX, you shouldn't see much of this effect.

Or you can see the vehicles stuttering as the move.

This can be caused by a number of issues, for example running with unlimited fps. Unfortunately, Simconnect only allows to run at the same frequency of the frame rate (not exactly but, the lower frequencies allowed, 6 hz or less are not nearly enough to have things moving smoothly ) so, if your fps is too high, you are forcing ALL running Simconnect apps to generate more traffic than required.

When there's too much traffic, commands are placed in a queue, so they are slightly delayed, resulting in a delay of the position updates of the vehicles. Of course, this affects all running apps but, since GSX is one that move things on screen, you can easily be mislead "GSX is stuttering" because, of course, if an airplane is running a non-visible simulation of a system, you can't possibly notice it's also affected by the same problem, since that stuttering is not affecting anything that moves on screen.

You can usually improve this by capping the fps in the sim, which will limit traffic over Simconnect, reducing the chance for all running apps to generate too much traffic.

[dogfighter2111]

Thank you for the reply, I appreciate the info.

This is MSFS itself which is trying to save memory by dropping and reloading textures which are going in and out of view. This handling has a cost, because dropping and reloading textures will cause having textures crossing again the RAM-VRAM barrier (the PCI bus), which will stall everything. Of course, this is valid for all objects in view, not just GSX vehicles, but you might not see this handling in effect until enough of VRAM is taken. But clearly, VRAM allocation is caused by everything summed together so, if you are on a default airport on a default airplane with only GSX, you shouldn't see much of this effect.

Unfortunately, it seems like the only solution in this regard is to reduce graphics settings to limit VRAM use.  :'(

This can be caused by a number of issues, for example running with unlimited fps. Unfortunately, Simconnect only allows to run at the same frequency of the frame rate (not exactly but, the lower frequencies allowed, 6 hz or less are not nearly enough to have things moving smoothly ) so, if your fps is too high, you are forcing ALL running Simconnect apps to generate more traffic than required.

When there's too much traffic, commands are placed in a queue, so they are slightly delayed, resulting in a delay of the position updates of the vehicles. Of course, this affects all running apps but, since GSX is one that move things on screen, you can easily be mislead "GSX is stuttering" because, of course, if an airplane is running a non-visible simulation of a system, you can't possibly notice it's also affected by the same problem, since that stuttering is not affecting anything that moves on screen.

You can usually improve this by capping the fps in the sim, which will limit traffic over Simconnect, reducing the chance for all running apps to generate too much traffic.

This is what I was after. Ultimately it is only GSX that makes it noticeable, which is what I meant in my initial post not that I thought GSX was the problem. I don't think I made that clear. 

I was unaware of how everything connected together, but thanks to the above info it makes sense now and ultimately limiting the FPS should reduce/avoid the issue I am having.

Thank you!