C3 Still occasional stuttering frame rate drop on Quest3

[Mikelleen]

Having flow Condor 2 in VR for several years, and running many contest with groups, one issue that seems to occur with not just me is occasional stuttering and drops in frame rate.

This occurs occasionally and is quite annoying but I learned to put up with it in C2. That being said I know from discussions with others during contests that I am not the only one suffering from this issue.

So I JUST bought a new computer with an AMD Ryzen 7 with 16GB DDR5 5600 RAM and RTX4070 with 8 GB of ram hoping that this issue would maybe go away. I am on Windows 11 build 23H2. I am running the Quest 3 at the default setting of 72FPS, direct USB connection.

Yet the occasional stuttering and drop in frame rate still persists in VR.
I also noted that Condor 3 is still limiting itself to using a max of 4GB GPU memory, in setup.

I was told once by a senior Condor competitor that he thought it was landscape loading to cache, which created the occasional lags, but I am on the latest NV M.2 SSD with 2 TB. The landscapes and OS are on the same SSD drive.

Any ideas on this? I'm kind of bummed that we are still limited to only 4GB GPU, but I do not think that is the issue, as looking at performance monitor I am not even using the full 4GB of GPU memory and I am also not close to using all my RAM or CPU utilization.

[janjansen]

There seems to be a performance issue when calculating thermals on modern AMD cpus:

https://www.condorsoaring.com/forums/vi ... 29&t=22312

Im guessing thats whats affecting you. If you make your own tasks, you can reduce the thermal activity and width of thermals (I think higher cloud base also helps as there will be less) and with most realistic settings, its not an issue; but on tasks with loads of wide thermals, it can bite.

Its not clear to me yet if this slow execution on AMD cpus only results in a reduced FPS on thermal heavy tasks, or also contributes to occasional stuttering, but I think its both. It doesnt seem to be landscape loading which I believe is now done in a background thread (and at least one person put their landscapes on a HDD doesnt seem to be affected more than SSD users, as long as the OS and condor is on a SSD), some else reported CPU spikes during the stutters, so it could be a CPU bottleneck, and if true, its likely affecting AMD users primarily.

I found that reducing visibility distance one notch helps quite a bit with the occasional stuttering with minimal impact on how it looks.

My best guess is that condor now loads landscape tiles in the background, but after loading calculates the thermals for that tile in the main loop and if this takes too long (on AMD), you get a stutter. If you reduce the visibility distance, condor needs to load a (lot) less tiles, has less thermals to calculate, so the impact is significantly reduced.

[Mikelleen]

So testing some more this morning, and I can confirm that the occasional drops in frame rate correspond directly with a sudden minor peak in CPU utilization.

Running the Quest 3 at default settings of 72Hz refresh rate, direct USB connection, I get periods of average CPU utilization (~50%) that does not waver +/- very much, then I'll get a quick increase in CPU of about 20% more, that lasts just a few seconds before returning to previous running average. This always corresponds to stuttering in VR, a drop in GPU utilization of about 20%, and a corresponding frame rate drop.

It looks to me that whatever calculations are occurring on the CPU, for weather, or whatever Condor is processing, when it needs to run a new calculation on 'whatever', it is not isolating that calculation from continuing image processing calculations.

I'm running a current gen Ryzen 7. I'm wondering if Condor is multi threading, as for example you can in DCS which has the ability to multi thread?

I don't know what's up, but it is disappointing that this issue is a carry over from Condor 2. Don't get me wrong, the development guys have done a lot of good work with C3, but this seems a problem, as the Ryzen 7 is a known good gaming chip. Weird this would be the opposite case for C3.

[janjansen]

I believe condor 3 does some light threading for background tasks (like loading landscape tiles), but its clearly single thread performance limited. Its easy to point to MSFS or DCS, but multi threading (and actually getting performance gains from it without thread sync performance regressions) is really hard, if it can even be done for some tasks. It took DCS what, 10 years or so? And thats with a team of ~200. Condor is a two man show, basically one dev, one 3d modeler/everything else, supported by volunteers.

Its also probably not even needed for condor. On most tasks if I remove GPU bottlenecks, and ensure I dont run in to the "AMD issue" I can get 300-500+ FPS. Its not worth it trying to make that 1000FPS, there are plenty more useful ways to spend developer time.

Now of course I really do hope the AMD zen3/4 issue gets resolved at some point (I own one myself) but I cant blame anyone for this. This is just so weird; condor runs great on basically any intel chip, it runs great on 5yr old budget Ryzen cpus. If I had tested that, I would have been absolutely convinced it would run flawlessly on more modern Ryzen implementations that are substantially faster at basically everything. Except condor as it turns out. Given how many CPU architectures are out there, not too mention how many GPU architecture, a small team cant test everything, you cant expect them to have a lab with every AMD and intel chip released in the last 10 years and have someone do performance analysis on them. And thats basically what it would have taken to uncover this one, that or just luck. AFAICT the entire (?) beta team just happens to have intel.

[Mikelleen]

I was not aware the Condor dev team was just a couple of guys and some volunteers.

Fantastic work for such a small team.

So maybe asking for multi-threading is a stretch, I do understand the complexities can be daunting, and probably not worth the effort as apparently it runs fine on either Intel architecture, or older AMD. I'm sure someone could figure out why this is occurring in current gen AMD Ryzen but it is beyond my development skill set for sure.

For me the solution is going to be returning my just purchased gaming laptop with Ryzen 7 and RTX4070, and buying a comparable system with Intel processor.

[timbaeyens]

In a time, long before, there were hybrids like this, combining intel and AMD cpu in 1 system:

ee40a9e011045781f7138cc99e8341def512ee43.jpg (101.79 KiB) Viewed 1118 times

[Fingers]

Having flow Condor 2 in VR for several years, and running many contest with groups, one issue that seems to occur with not just me is occasional stuttering and drops in frame rate.

This occurs occasionally and is quite annoying but I learned to put up with it in C2. That being said I know from discussions with others during contests that I am not the only one suffering from this issue.

So I JUST bought a new computer with an AMD Ryzen 7 with 16GB DDR5 5600 RAM and RTX4070 with 8 GB of ram hoping that this issue would maybe go away. I am on Windows 11 build 23H2. I am running the Quest 3 at the default setting of 72FPS, direct USB connection.

Yet the occasional stuttering and drop in frame rate still persists in VR.
I also noted that Condor 3 is still limiting itself to using a max of 4GB GPU memory, in setup.

I was told once by a senior Condor competitor that he thought it was landscape loading to cache, which created the occasional lags, but I am on the latest NV M.2 SSD with 2 TB. The landscapes and OS are on the same SSD drive.

Any ideas on this? I'm kind of bummed that we are still limited to only 4GB GPU, but I do not think that is the issue, as looking at performance monitor I am not even using the full 4GB of GPU memory and I am also not close to using all my RAM or CPU utilization.

I am still on C2 and the stutter does seem to be when loading in the furniture, be it clouds or land. I have not dived into it but are there no ini or json files to tweek?

[janjansen]

You can tweak the FPL, as Im fairly sure C2 and C3 have the same issue, and it appears related to thermal calculations that happen each time a new part of the landscape is loaded. The issue becomes worse the higher the thermal activity is (cloud base may play a role too, as lower base means more thermals).

This is being looked at for C3, and but I wouldnt expect a fix for C2. BTW, the AMD ryzen issue mentioned above has been completely fixed.

[Bre901]

It's probably aggravated in C3 because in C2 the number of thermals was more or less fixed, so you had to set activity high to have a decent density on large landscapes (e.g. AA2) ; whereas in C3, it's the density that appears to be more or less fixed, hence high activity is no longer needed as a workaround and becomes detrimental when used with low cloud base, because of a very high CPU usage

If you are not convinced, just look at the thermal helpers with max visibility distance with activity=high and cloud base ~1000m AGL on the same airport on a large landscape in C2 and C3

[janjansen]

whereas in C3, it's the density that appears to be more or less fixed, hence high activity is no longer needed as a workaround

Im not sure I agree here. In fact, I often find it difficult to obtain "enough" thermals in C3 flat areas without cranking the settings to high. But I think the logic of what "flats activity" means has changed. Im not sure here, but in C2 I think this had something to do with how much influence the thermal map had? Turning flat activity to low in C2 didnt necessarily mean you had less thermals. In C3 it does, best I can tell, actual thermal activity in flats is determined by the lowest of thermal activity and flats activity. At least it seemed like that in areas and tasks I experimented with.

edit: quickly tried in C2, seems to work about the same, so I may be misremembering something or its even from C1.. I could swear once upon time changing flats activity would cause thermals to appear or not over sea.

[EDB]

I could swear once upon time changing flats activity would cause thermals to appear or not over sea.

In sceneries without a Thermal map you would see the most clouds over the sea with Flat Activity at a higher setting. Because the sea is the flattest area in a landscape. Only when the landscape had a thermal map (with 0-5% over sea) the number of thermals above the sea where and stayed reduced.

[alexlee]

So testing some more this morning, and I can confirm that the occasional drops in frame rate correspond directly with a sudden minor peak in CPU utilization.

Running the Quest 3 at default settings of 72Hz refresh rate, direct USB connection, I get periods of average CPU utilization (~50%) that does not waver +/- very much, then I'll get a quick increase in CPU of about 20% more, that lasts just a few seconds before returning to previous running average. This always corresponds to stuttering in VR, a drop in GPU utilization of about 20%, and a corresponding frame rate drop.

It looks to me that whatever calculations are occurring on the CPU, for weather, or whatever Condor is processing, when it needs to run a new calculation on 'whatever', it is not isolating that calculation from continuing image processing calculations.

I'm running a current gen Ryzen 7. I'm wondering if Condor is multi threading, as for example you can in DCS which has the ability to multi thread?

I don't know what's up, but it is disappointing that this issue is a carry over from Condor 2. Don't get me wrong, the development guys have done a lot of good work with C3, but this seems a problem, as the Ryzen 7 is a known good gaming chip. Weird this would be the opposite case for C3.

I absolutely agree! I feel the same way. I respect that there is a small team, who is has main jobs and do the condor thing on the side. But what I really don't understand is releasing a new software with a main bug from the previous version. I really expected this was gone. So as many many others. It is not satisfying and I don't want to get the answer, "well lets reduce your settings and you're good to go"or" it's my fault as organizer because you put everthing on max, which is absolutely NOT TRUE to point out . This is like buying a new car what is limited to 100 km/h. I don't want to hear excuses, lets get this done! And by the way what I also don't understand is why the clubclass doesn't have LX ? Guys what is going on?