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Sekkha

Systematic stutter few seconds after liftoff - P3D V3.4

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Hi all,

first of all I would like to say thank you to the whole PMDG team for this awesome product.

I started simming with the FS95 more than 20 years ago and since the very first day I was hoping that one day a 747-400 simulation like the one you now created would become possible...
So now that "one day" has come... I just cant believe how good it is in every aspect (it looks great, it sounds great, it feels great, documentation is outstanding etc...)


Second I would like to report a little issue I found  at least on my system:

I observed that I got a systematic stutter (fps drop to 7)  a few seconds after liftoff at about 30 feet radio altitude. This stutter did always happen when I did a complete preflight. However sometimes when I just went flying without doing all preflight steps it wouldnt occur.

This happened regardless of scenery (default and addon), weather and everything else apart from the airplane (but on all models / liveries that I tested)

After several days of testing I could finally isolate the problem:

And its surprisingly (at least for me) related to the nav and strobe lights.Whenever I take off leaving both lights off, the stutter wont occur, whenever I take off with both lights on it will.

I subsequently also found out that this stutter can be triggered even on the ground by switching both lights on and then back to off. As soon as I switch the second one to off, fps will drop to 7......

Additionally I now observed several youtube videos from other simmers and it seems like it might be happening there as well (for exampel here

at 1:14 - 1:15)

Can someone else verify that?

 


While its not a problem for me any longer because I just can leave  those lights off it might be interesting to look into it....

thanks in advance and regards
Marinus Gerst

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A lot of logic wanting to switch from ground mode into air mode... all at the same time.

 

I don't think it's pmdg's fault. Blame our old simulator that can't provide efficient processing power.

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I am not talking about anybodys fault, just describing what is happening :wink:

 

 when I take off with those lights switched off  all logic seem to switch perfectly to air mode without producing a stutter (with Lnav , Vnav end everything engaged)

 

So there is a specific problem with those lights (at least on my system). Also the fact that  fps drop can be produced even on ground as I described above seems to indicate that.

 

Marinus Gerst

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A lot of logic wanting to switch from ground mode into air mode... all at the same time.

 

I don't think it's pmdg's fault. Blame our old simulator that can't provide efficient processing power.

 

Exaclty 100% absolutely nothing to do with PMDG product

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Marinus,

 

What are your system specs? Do you have your settings maxed out and do you get similar symptoms with other PMDG aircraft?

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That is something I've never seen..., ditto questions regarding your system and configuration.

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Steve, I dont have any other PMDG aircraft to compare...

My specs are Win7 Pro, I5 4760K @ 3.8 Ghz, GTX 750 Ti, Asus Z97

 

My settings are low to medium , nothing maxed out except scenery density,  only 1280 x 1024 resolution due to my 4:3 screen...

Unless in heavy weather I am getting perfect smooth 22-30 fps without stutters with the 747...

 

Marinus Gerst

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This seems to be related to some kind of FSX internal memory/thread scheduling issues, could be related to Windows or graphics driver as well. My PC is absolutely crap but runs NGX at 20-40fps. On 744v3 it sometimes run OK (24FPS, barely qualifies for film speed), but sometimes the external view drops to single digit with significant uneven stuttering, tuning down the settings does nothing at all. The spot camera is jittering back and forth so I know it is the FSX main thread stuttering. It could be that PMDG maxed out the aging FSX (as they have done so before) or my low-spec PC, or just a bug.

I'm getting a new PC anyway, it could "brute force" through this, but I hope PMDG would investigate and release a patch if possible.

 

Tom

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Wonder if it has something to do with the strobes/nav lights no longer illuminating the ground at that height? Like the sim "de-loads" the effect and causes it to stutter. Would explain why it doesn't happen with nav/stobes off. 

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Noticed the same during my takeoffs as well. Not a big issue, but I believe it is related to the QOTSII because it doesn't happen in 

any other addon aircraft I have installed.

Would like to see a response from the team on this issue ;) 

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I don't recall anyone on the team mentioning it, and as for my self I've not noticed it.

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its crazy..and .its just a little more complex than I described in my first post.

 

If I wouldnt have repeated that dozens of times now I would think it is impossible, but that cant be by chance....

 

In order to not get that stutter on takeoff I must load a flight or aiframe with a panel state, where those lights are off on loading and then not touch them at all (If I switch them on and then off again I will get the stutter)

 

For several reasons I uninstalled P3D completely this weekend and after reinstalling it I just installed QOTSII as the very only addon. And it still happens....(but not on other aircraft like AS A319 installed afterwards)

 

As I said in my first post. Not a big issue at all, but driving me crazy because I dont understand it :)

 

Marinus Gerst

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I don't recall anyone on the team mentioning it, and as for my self I've not noticed it.

That is why we are mentioning it for the team to have a look at it and maybe reproduce it. Might just send in a ticket to get some support on it. Not a big issue, but had been nice to solve it.

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Is there an option to completely disable the nav and strobe lights illuminating the ground? I know there's an option to disable daytime display of the effect, but I don't see one to remove the effect completely. Maybe worth a try to change that setting from whatever you have?? It's on page 7/10 in the PMDG Options menu.

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