FlightSim Development Group

Hi Thorsten, just bought DTTJ via Aerosoft, but I am struggling with my FPS... With my current settings I have 30 FPS at all large airports (EDDF, LFPG etc.) but I get 20s at DTTJ... Ground shadows are disabled, scenery complexity is set to normal... I think the main terminal is heavy on FPS here. Any ideas to help me?

My specs:
Intel Core i7 950, 6GB ram, Geforce GTX275, Intel SSD

I also looked into the textures, but they seem to be fine. Only thing I see in the scenery folder is a BGL file of 36MB (!)...

Could you please se the scenery density to different settings and report at which setting you get a bigger-than-expected impact? The scenery is made so that with each slider setting the number of objects displayed on the airport grows.
Don't worry about that big file, it's a library that contains most of the scenery objects.

Hi Thorsten, below are my findings. Normal I have FPS locked @ 30 FPS, but for the test I put it to unlimited.

Default Cessna, clear weather, AI at 100%
-----------------------------------------
DFS Amsterdam Schiphol
- Normal: 38 - 42 FPS
- Dense: 38 -42 FPS
- Very dense: 38 - 42 FPS
- Extremely dense: 38 - 42 FPS

Aerosoft Zürich X
- Normal: 33 - 36 FPS
- Dense: 33 - 36 FPS
- Very dense: 33 - 36 FPS
- Extremely dense: 33 - 36 FPS

FSDG Djerba X
- Normal: 35 - 39 FPS
- Dense: 29 -32 FPS
- Very dense: 27 - 29 FPS
- Extremely dense: 23 - 25 FPS

Qualitywings 757, clear weather, AI at 100%
-------------------------------------------
DFS Amsterdam Schiphol
- Normal: 27 - 34 FPS
- Dense: 27 - 34 FPS
- Very dense: 27 - 34 FPS
- Extremely dense: 27 - 34 FPS

Aerosoft Zürich X
- Normal: 24 - 30 FPS
- Dense: 24 - 30 FPS
- Very dense: 24 - 30 FPS
- Extremely dense: 24 - 30 FPS

FSDG Djerba X
- Normal: 24 - 30 FPS
- Dense: 22 -28 FPS
- Very dense: 19 - 24 FPS
- Extremely dense: 18 - 21 FPS

In summary I draw the following conclusions:
- FSDG makes use of the FS9 settings to control complexity of the scenery, while the other airport designers don't
- Other airports give me more FPS with more AI (since the airport is larger, more AI is shown than at DTTJ)
- Even at normal complexity FPS drop to 24, causing stuttering

So, is there a way to boost my FPS, for example adding some settings, or exclude some less important BGL files?

I'm always surprised so few developers make use of that slider, because this is really why it's there in the first place: to enable the user to control the number of objects displayed and the performance impact he gets from them. Now I see that the impact is bigger than you would expect and does not seem to be related to any individual file or object. It seems FS9 is way more sensible to polygons than FSX is. Even though this might sound surprising, Djerba has more polys than some bigger airports like Amsterdam.
That does not explain why the impact is so very different on different PCs. Probably the gfx card does not like the number of polys.
At the moment I would advise to make use of the scenery slider, even more as it will probably only affect the DTTJ scenery settings for the reason mentioned above.

Still, 24fps are more than the eye can handle, or to be precise, it's the exact number of frames you need to get a perfectly fluid motion. I guess you're relating to (micro) stutters of the scenery then if you write " FPS drop to 24, causing stuttering"?
Could you please describe those stutters? When and where do they happen?

Hi Thorsten, thanks for the explanation. My FPS vary between the appr. 24 and 30 when the airport is in sight. This causes little hick-ups when landing... It feels like some sort of delays, and with a manual approach... The only airport where I am experiencing the same is Antalya X... So indeed probably has to do something with the polygons of the terminal.

I'm not happy with that obviously. But it doesn't seem like we made a mistake with one of the files. I guess the poly amount is just rather big in this case. If it does not affect other sceneries, go with a "dense" setting. You will not miss any important feature, only some vegetation, some vehicles and some details like the telephone poles.

horst18519 wrote:I'm not happy with that obviously. But it doesn't seem like we made a mistake with one of the files. I guess the poly amount is just rather big in this case. If it does not affect other sceneries, go with a "dense" setting. You will not miss any important feature, only some vegetation, some vehicles and some details like the telephone poles.

Hi Thorsten, a dense setting is definately a no go... No I have set it to 'normal'. I hope I won't miss too much at other airports and I really hope you can look into some optimization.

Hi Thorsten, Emilios,

I finally found the issue! I started with the default Cessna, and I only got lower FPS when in cockpit view. I played with my video card settings, but not much result. Then I looked at my FS9.cfg and noticed some additions. I removed some lines and after removing the line 'PanelAsTexture=0' my FPS are steady at 30FPS! Also other airports benefit from it!

Maybe this will help other users who are suffering the same issue!

Now there's no holding back in buying LGIR for me

Wow, that is a very interesting find indeed.

Even though I have no idea why this would create trouble with addon sceneries, I sure hope that it solves potential low fps for users of all kinds of sceneries, not only our DTTJ.

Would be interesting to learn if it helps other users as well.