Known VR issue, but to be clear...

  • Hi, I write this thread 1) to put a picture on the culprit 2) to ask VR users to agree or not so it could become a priority (another... I know) to resolve it.

    First of all, I give the congratulations that IPACS team deserves for all the work done and in progress, that lead to this awesome VFR VR experience.

    Now the known issue... the stutters. It's been disscussed two threads below, I and others posted about it before.

    The VR VFR experience is near to perfect but this issue is the only performance issue I know that separate the actual rendering from perfection.

    So here is afterburner monitoring of a short fly above switzerland, starting from Iterlaken, aerobatic full afterburner over mountains tops and landing not far. Settings are : maxed out and 2.0 SS pixel density (EDIT : no in fact it was 1.5 pixel density. At 2.0 GPU overloads ), 30% clouds cumulus and cirrus, oculus rift :

    As you can see, with these settings, gpu and cpu are well used but handle it perfectly.... but the FPS curve (images par seconde, IPS) is not 90fps flat : you can see the stutters's downward peaks. (each time stutter occures the fps point to zero during the period the stutter lasts). It's a hurt regarding the awesome look and perf of Aerofly FS 2.

    So I hope all the VR users that agree with that and want it to be resolved will just post, even if developpers know it and surely know what to do... but there are priorities, each of developpers having only two arms. My hope is that it will be solved as soon as possible.

    My specs : I7 7700K@4.8ghz, 1080Ti gaming x, 32GB 3200mhz, ssd, win10

    To compare here is the afterburner monitoring of Prepar3d - same location / fly - similar conditions (LOD10 mesh, 2meters photoreal textures, no autogen trees - P3D trees are too big and ugly color on photoreal - but almost full autogen buildings, almost same clouds coverage and SS pixel density 1.5 - 2.0 overload gpu -) with a flat 90 fps curve with oculus rift :


  • Hi Oldar, it's not less stutters .... it's not at all.

    The issue you can have with P3D is fps problems due to overloading gpu or, more usually, cpu (1 thread/core the most used).

    P3dv4 is able to run great in VR or screen - it's just a matter of setting well the gpu-heavy and the cpu-heavy options, so both cpu and gpu are well used and one doesn't bottleneck the other.

    But no stutter issue at all, that is the actual only performance problem of Aerofly FS 2. BTW you can see it with FPS curves for one and the other.

    • Official Post

    Let's not begin a comparison war here. I'm not too sure of the point that you are trying to make here.

    I have 4 testing machines to test developer versions is Aerofly FS2 and one of them happens to be an i7 4.2, GTX 1080Ti, 32gb memory, and a 25TB fiber connected NAS. Running in VR (Oculus VR mode) with CV1, RSF 2.0, max everything (insane shadows), many clouds. FPS is a solid 90 in most circumstances.

    There will be some micro-stuttering in areas near airports or high capacity areas when the models have to load into memory. The loading is set up for future growth, so once ATC and some other graphical enhancements are added it will remain high FPS. There is a lot of overhead remaining in the current configuration with some room to make some tweaks here and there.

    If you are running VR with Steam VR mode you will see a bit more stuttering as Vive/Steam VR has more overhead to tend with than Oculus. Eventually both platforms will be further improved over time though.

    IPACS Development Team Member

    I'm just a cook, I don't own the restaurant.
    On behalf of Torsten, Marc, and the rest of the IPACS team, we would all like to thank you for your continued support.



  • Hi drhotwing1,

    no comparison war at all - no purpose - the monitoring comparison is there to show the fps curve in a flightsim and cpu/gpu usage when there is no stutter problem.

    Aerofly FS 2 has a stutter problem, a thing that is not normal and that can be resolved only with work on the "coding" or "programmation" of the game.

    The point I am trying to make here, as you doubt, is to point at a problem trying to have, or not, a consensus that there is a problem (I'm not alone pointing at this and I make this thread to picture it the best way I can) in the purpose of making developpers fixing it. I'm sure it would be positive not only for my own use ?

    I don't talk about general performances of Aerofly FS 2, everyone, users or 3rd party developper, admitts it's great. Stutters are another problem (they happens whatever the settings or number of rendering objects) that is performance wise but nothing to do with max FPS wich are great.

    I thought I was clear and short as possible with this thread ?

    If you say me (us!) in the name of IPACS that, technically wise, yes there is some stutters, and no there is nothing we will do about it we think it's normal...So ok I (we) have an answer (bad for me) and thread deserves to be closed.

    What I would like to hear is yes, there is an issue, we will resolve it when it will be it's turn.

    • Official Post

    As you know, I work directly for IPACS and one of my many duties is testing. In testing I mean in many different circumstances under many different configurations, and the only stuttering noticed (and noted) was in VR in Steam VR mode. There are some instances that could cause some stuttering, but nothing to affect the overall experience, is the clouds. The current clouds can certainly be optimized some but they can't be touched or changed because it's not IPACS code. Once a better solution is introduced the performance will be improved.

    The other area I already pointed out is when scenery is loaded into memory, this is more apparent when around more heavy model areas such as airports.

    There will be some performance issues in the NYC area and around LOWI on less optimal computers but that can be rectified by lowering your graphical settings.

    One other thing that I mentioned is that there will be more performance tweaks over time as you have to remember here that we are still in early access.

    If you are referring "stuttering" as something that you have to use monitoring devices to actually see, or stuttering that the naked eye can see, if the latter there would be many users out there complaining about it rather than complimenting the performance.

    Don't get me wrong here as I respect your views towards this topic but we have to have something tangible to go after here.

    I'm not trying to be defensive here, I only look at facts, always.

  • Hi again,

    I use only oculus vr mode, I can use clouds or no clouds and have this stutters, it's not related with settings or number of rendering objects.

    Yes they are probably related with some loading process (objects or textures or something else) - I don't know I just can see it (and I guess any VR user can cause it's the only thing, when settings / config allow enough FPS, that downgrade the VR experience : these short freezes regularly jump to your sight) and of course I monitored it because I saw it and not the opposite.

    Don't get me wrong to because I can't complimente better than saying that this issue is, in my opinion, the only thing that separate AFFS2 from the perfection (VR VFR experience wise !) - to be fair I should have said, in my stutters comparaison with P3D, that on others aspects VR experience is better in most ways with AFFS2 (but the point was stutters)

    It's not a point of how many compliment / how many make critics, I am in the two cases and most of us that ask things are, and I want to see AFFS2 being improved where it needs to from my user's experience point of view (here VR VFR wise).

    It's a point of do most of us VR users experience this issue (that's why the thread) and if so can you be precise concerning its solving (you say there will be more performance tweaks but what about this particular point ? once again the only issue I can see performance wise)


  • I dont have stutters in occulus vr mode.. i7 4790k oc to 4.5ghz gtx 1080 16gb ram... i dont run cumulus clouds cause they look silly at the moment... but everything else is maxed. I like ss at 1.5 cant really tell a difference at 2.0.

    two applications in the background do have an effect.. Mouse without borders cant be running and f.lux cant be changing my screen color.. other than that the game runs nearly flawlessly in almost all circumstances (NYC brings it to it's knees but i still run smoothly)

  • Hi, I should have specify that these stutters are issue with speed increasing.

    At very low speed (or with slow Aircraft) they exists but not a problem (no real perception).

    But take a F-18 or F-15 and go fast and there they impact the experience.

    On the fly I monitored I was full afterburner almost all the time.

  • @OP,

    Then you may simply be seeing the small dips in performance when new scenery cells have to be loaded. Scenery in front of you has to be moved from SDD to GPU memory. This issue, of course, depends on the complexity of the scenery in your flying area.

  • I fly f-15s 100 feet off the deck at mach 2.2

    Enjoy it until Mach drag is implemented into Aerofly FS2. ;)

    The real F-15E top speed at S.L. is 'only' M1.2 at FL400 on the other hand M2.4 is possible.

  • I have to say that I occasionally have stutterers too, but not regularly. I believe the others that they have none. So I assume that my PC caused this problem. Maybe my CPU is too weak?

    Intel Core i5-4670K @ 4.2 GHz

    8GB Gainward GeForce GTX 1080 Phoenix GLH

    Crucial Ballistix Sport DIMM Kit 16GB, DDR3-1600 RAM

    Samsung SSD 840 - 250GB

    Windows 10 64 bit

    SS is at 1.6

    Clouds are off

    Shadows and trees on middle

    Buildings on high

    Rest on ultra

  • I have come to the conclusion that some people are much more likely to see stutters than others under the same conditions. I think some people's eye/brain setup are just more sensitive to the phenomenon. I think there is a different threshold at which different people perceive them. That is just my opinion from following this debate and noticing or not noticing them myself ever since the "stuttering" issue started being discussed about 15 years ago. Before that, frame rates were generally too low for stutters to be an issue!

  • yes whitav8 as you and drhotwing say I believe this issue comes from some kind of loading process or data transfer process - I believe it's always the case with stutters - but stutters occures frequently whatever the complexity, even if it has a certain impact on it.

    No jk1895 I don't think your cpu is involved in stutters, it's not related to performance or settings - I had i5 4460 / gtx 970 / HDD and now i7 7700k / gtx 1080Ti / SSD, the performances changed but not the stutters, they happen with screen or VR.

    I'm more satisfied than disappointed - it's just that without it, VR VFR wise, it would be perfect. But a "small" issue, that I juge very annoying in VR, can involve a big work / coding change or maybe something not possible for now. I just point : it exists, without it it would be perfect, it's not a fatality (compare with "comparable" sim), and if I don't mistake about this issue existing (some don't experience it) - can it be resolved it would be great (only if it's not just for 1 annoying customer...)

    Yes bbrz for now speed and G's are at no cost or limit.... it won't last long.

  • I also have a stutter every now and then but this is clearly related to new things being loading into the memory. Usually things are utterly smooth, as in real life. If you want to see real stutters, try FSX or P3D: I had stutters in those sims all the time. But as Oldar says: some are bothered with this (I was!) and some not. I am very happy with the real life smoothness of Aerofly FS 2 and I can live with an occasional stutter. Frequent stutters would kill the immersion for me.

  • J van E - I don't agree what you say about real stutters in P3D, even if I only have the latest v4 (probably things changed), because in VR there are no one (look at the VR FPS graph I posted on top). But ok I understand what you say. It's probably a small issue and certainly we have different expériences.

    For now with the posts I read here stutters are not a problem, and drhotwing mostly said "some exists in some case" and "more performance tweak are to come". OK. I knew that but I was concerned about IPACS communication about this specific point, as I see it's the only "performance" issue that, for me, hurt the VR experience, and as for me it happens permanently (look the AFFS2 FPS curve - it's absolutely recurrent).

    Of course using a screen, going light with settings, flying slow and so on minimize the impact of stutters to probably imperceptible but I report a specific case

    But 2 or 3 users bothered about that of course means nothing.

    • Official Post

    I provided you with a clear response on your topic and that we will of course tweak performance during the development process. I'm still not too sure what point you are trying to make here.

    • Official Post

    OK, for the good of the forum, i'm going to close this thread.

    To the OP, your mention of stuttering has been noted and if there is anything worth improving upon it will certainly be done.

    IPACS Development Team Member

    I'm just a cook, I don't own the restaurant.
    On behalf of Torsten, Marc, and the rest of the IPACS team, we would all like to thank you for your continued support.