This and I am pretty sure it wont take long anymore until the true reason for the performance increase is found. Reduced TLOD with the same settings, more agressive culling, reduced roadtraffic or shiptraffic, whatever it might be. There is no free lunch and a 25% performance increase or even more never comes just like that. The SU4 beta testers just did not yet find it...

Il y a 12 heures, abrams_tank a dit :

 

Thanks for this video.

I've noticed that with SU3 or SU4 Beta and a top-of-the-line configuration: Ryzen 7 9800X3D + 64 GB DDR5 RAM + MSI GeForce RTX 5090, the stuttering is still terribly and desperately present (starting at 4:25). Personally, I'd prefer 30 fps without stuttering than 70 fps with stuttering.
Just my opinion.

24 minutes ago, AnkH said:

This and I am pretty sure it wont take long anymore until the true reason for the performance increase is found. Reduced TLOD with the same settings, more agressive culling, reduced roadtraffic or shiptraffic, whatever it might be. There is no free lunch and a 25% performance increase or even more never comes just like that. The SU4 beta testers just did not yet find it...

Yeah it's never a "free lunch" the blurry ground texture LODs in recent months are definite downgrade to aid better performance.

1 hour ago, AnkH said:

This and I am pretty sure it wont take long anymore until the true reason for the performance increase is found. Reduced TLOD with the same settings, more agressive culling, reduced roadtraffic or shiptraffic, whatever it might be. There is no free lunch and a 25% performance increase or even more never comes just like that. The SU4 beta testers just did not yet find it...

I've done more than 20 flights now in SU4 with the Fenix and my sim looks better than ever. If anything I can see more road and ship traffic, terrain, objects and textures look crisp and clear all the way to the horizon (200 base, AutoFPS to have 100 on the ground and 400 at altitude). I've managed to crank up BATC traffic sliders and see more AI aircraft than ever. Yesterday evening I had a steady flow of AI aircraft landing at KDFW, 3 runways used in parallel and multiple aircraft lined up with separation. Lights were visible far into the distance - it was an incredible sight and I actually stopped for a moment to think how far we have come since the days of FS98. For me SU4 just brings it all together - amazing performance and fantastic visuals.

MS have made it clear a while ago that SU4 will be focused almost completely on performance and better leveraging modern hardware. It's clear as day that the sim now makes much better use of the GPU and I can see my 4090 utilised around 90% many times. Previously I rarely saw it used more than 30%. The devs have also explained a while ago that SU4 will focus on optimising multi-threading and load balancing and alleviating the main thread bottleneck. So the big performance increase that pretty much everyone is reporting isn't by accident, it's by design and it works amazingly well. 

Edited September 16, 2025Sep 16 by Speedbird 217

1 hour ago, AnkH said:

This and I am pretty sure it wont take long anymore until the true reason for the performance increase is found. Reduced TLOD with the same settings, more agressive culling, reduced roadtraffic or shiptraffic, whatever it might be. There is no free lunch and a 25% performance increase or even more never comes just like that. 

You can just read the release note on how they did it:

 

Quote

• Optimized grass rendering.
• Performance optimizations on airport, atc, aircraft and scenery.
• Performance optimization of boat and road traffic.
• Performance optimization of the sim flow code.
• Optimization of main CPU thread.
• Optimization of the main CPU code for event display.
• Optimized scenery objects culling compute.
• Optimization of graphic user interface (menu pages).

 

 

1 hour ago, AnkH said:

The SU4 beta testers just did not yet find it...

It's been a week and the SU4 beta testers haven't found it yet.  So I guess it must be a good optimization fix, because if after a week, the SU4 beta testers still have not found it, then it's probably not noticeable to the human eye, and thus whatever optimization they did is worth it.

If the optimization they did was immediately noticeable, or was noticeable shortly after the release of the SU4 beta, then it might not have been a worthwhile optimization. If a week has passed and the SU4 testers still haven't figured out what the compromise was, then I think it's probably a worthwhile optimization because a whole week has passed, and nobody has really noticed the degradation in visuals.

 

Edited September 16, 2025Sep 16 by abrams_tank

1 hour ago, Area said:

Thanks for this video.

I've noticed that with SU3 or SU4 Beta and a top-of-the-line configuration: Ryzen 7 9800X3D + 64 GB DDR5 RAM + MSI GeForce RTX 5090, the stuttering is still terribly and desperately present (starting at 4:25). Personally, I'd prefer 30 fps without stuttering than 70 fps with stuttering.
Just my opinion.

The problem is that you can only choose between 70 fps with stuttering and 30 fps with stuttering 🤣

There are often misconceptions about stuttering, it gets confused with framerate fluctuation and juddering. The first can be cured with a framerate limiter, the second with GSync or VSync at a fixed refresh rate lower than the minimum framerate deliverable by the system.

For stuttering instead, there is NO CURE. Stuttering is when the frame delivery briefly STOPS, even if your average framerate is 200 fps, even if the 200 fps are measured in a short interval of half second or less. When the framerate gets to zero or single-digit values, there is no parachute, no trick that can maintain the feeling of smoothness.

Only the developers can intervene in this case, by optimizing the code to avoid bottlenecks in the pipeline that feeds the monitor with fresh frames.

Hope you guys are all righty then 😊👍

This looks promising. I ended up opting out of the beta so I could fly some of my current favorite planes. But may jump back in...

17 minutes ago, Sonosusto said:

This looks promising. I ended up opting out of the beta so I could fly some of my current favorite planes. But may jump back in...

Unless you are absolutely desperate for some kind of performance gain, it might not be worth it yet. I have opted out and gone back to SU3.

Pretty much all I do in FS is make short flights in the Fenix A320, usually between airports for which I have installed detailed add-ons such as EGLL and LFMN.

In my particular use case, the only downside I’ve noticed with SU4 is that not all the airbridges are depicted, or operable, in the airports.  

Apart from that, I have not noticed any attenuation in visual quality or detail, or any sacrifice in traffic density or LOD or the like. In fact, if anything, my impression is that there is more traffic on the roads and more ships. 

Performance was fine with SU3 but with SU4 it has improved appreciably as measured by the built-in FPS counter, from ~80fps in SU3 to over 100fps in SU4 at my “stress test” location, 4k but using DLSS and FG of course. In the cruise I have seen the framerate exceeding 150fps: unprecedented in my experience. Under stressful conditions, takeoff and approach and finals, the framerate fluctuates less, and within a smaller range, than SU3, meaning that the overall effect is more smooth. 

I have not noticed any “stutters”: I’m not claiming there are zero stutters, but if there are any stutters then I haven’t found them to be a distraction (unlike some previous versions).

Edited September 16, 2025Sep 16 by tfm

38 minutes ago, Sonosusto said:

This looks promising. I ended up opting out of the beta so I could fly some of my current favorite planes. But may jump back in...

The Fenix is working flawlessly as far as i can tell. 

Ini A350 works great, has two small easy bugs - when you load in to the plane, go to the Maintenance tab in the OIS, and renew the batteries and engine oil. Once this is done (has to be done on every flight at first load, is a bug), the plane behaves as you'd expect. 

Haven't tried too many other planes in detail, but most seem to work. 

1 hour ago, tfm said:

Pretty much all I do in FS is make short flights in the Fenix A320, usually between airports for which I have installed detailed add-ons such as EGLL and LFMN.

In my particular use case, the only downside I’ve noticed with SU4 is that not all the airbridges are depicted, or operable, in the airports.  

Apart from that, I have not noticed any attenuation in visual quality or detail, or any sacrifice in traffic density or LOD or the like. In fact, if anything, my impression is that there is more traffic on the roads and more ships. 

Performance was fine with SU3 but with SU4 it has improved appreciably as measured by the built-in FPS counter, from ~80fps in SU3 to over 100fps in SU4 at my “stress test” location, 4k but using DLSS and FG of course. In the cruise I have seen the framerate exceeding 150fps: unprecedented in my experience. Under stressful conditions, takeoff and approach and finals, the framerate fluctuates less, and within a smaller range, than SU3, meaning that the overall effect is more smooth. 

I have not noticed any “stutters”: I’m not claiming there are zero stutters, but if there are any stutters then I haven’t found them to be a distraction (unlike some previous versions).

in the vid it also showed more fps with an increased load on cpu and gpu. do you also observe this?

53 minutes ago, bigifooti said:

in the vid it also showed more fps with an increased load on cpu and gpu. do you also observe this?

Only by inference from the observed framerate delta between v3 and v4b: I don’t run monitoring software to indicate those metrics in real time. 

1 hour ago, bigifooti said:

in the vid it also showed more fps with an increased load on cpu and gpu. do you also observe this?

I have, yes. My 4090 now reaches 99% usage and stays there.

I have upgraded my CPU to a 9800X3d, so that helps.

However, I also ran SU3 on this same machine for a day or so, and that most definitely (I was benchmarking my new PC, so I know) used less of the CPU and the GPU, and generally delivered worse performance than SU4 beta. 

28 minutes ago, JonathanC said:

I have, yes. My 4090 now reaches 99% usage and stays there.

I have upgraded my CPU to a 9800X3d, so that helps.

However, I also ran SU3 on this same machine for a day or so, and that most definitely (I was benchmarking my new PC, so I know) used less of the CPU and the GPU, and generally delivered worse performance than SU4 beta. 

This is key and as impactful as when P3D went from 32 bit to 64bit imho... With everything else being equal or greater to 2020 being able to fully utilize all my HW is a critical differentiator to a GPU running at 50%