Ok, I did some "tests" recently. So far, I usually avoided flying in the night as I do want to see something. My DL performance is extremely diverse: while I get solid 22-25 FPS in LEBL from Aerosoft (including AI traffic...), my FPS are down to below 10FPS for example on JustSims LFMN. Also in my case the "panning around" trick in the external view does not do anything in favour of the FPS if they are really low. Actually, I do not see any effect at all by panning around... Only thing that brings FPS slightly up is changing from 4xSSAA to 4xMSAA, but also with MSAA, the performance for example in LFMN is still unbearable...

@AnkH

Interesting, what is your video card and what are your GPU's cores load when this is happening?

Regards,

Simbol 

I think it was mentioned before and might even have been in this thread that it's what the dynamic lights will light up that determines how bad the FPS hit will be. I guess for any airport using some older techniques for the scenery the hit might be worse than for a brand new airport that was built using P3Dv4 tools only.

I'm far from an expert but this sounds like a logical explanation to me why the difference is so big from one airport to next when it comes to DL.

40 minutes ago, AnkH said:

My DL performance is extremely diverse: while I get solid 22-25 FPS in LEBL from Aerosoft (including AI traffic...), my FPS are down to below 10FPS for example on JustSims LFMN.

Scenery content providers are still learning the ins/outs of DL optimizations so you will see wide variance in FPS.  For example Aerosoft's EGLL Pro is very well optimized for P3D V4 DL (as are some more recent airports, KACK for example, and others).  The size of the light cone and distance will make a huge impact of FPS, content providers will need to manage these values very carefully as even a very small change in cone size and distance could result in a very big FPS impact.

I would NOT use 4XSSAA with DL for current crop of GPUs, I use 8XMSAA.

Cheers, Rob.

Generally speaking, it seems like every time a sim developer (not just LM) introduces a new major feature, the initial enthusiasm is eventually tempered by the fact that the feature puts additional strains on the hardware. Since most of the new features tend to stress the GPU more than the CPU, the only long term solution is to upgrade one's video card. At least none of the sim developers are relying on new Intel CPUs anymore for performance gains. Besides, a new Intel CPU is an example of planned obsolescence since it  usually also requires new RAM and a new motherboard.

Maybe all developers at LM have DGX1 computers!

8 hours ago, simbol said:

Maybe all developers at LM have DGX1 computers!

Or just the DGX station with only 4 V100 GPUs instead of 8 ... bargain at $69,000 vs. the $149,000 DGX-1

And before the "it's cheaper to fly real world", depends on what you fly and how often.

On the positive side, 5 years from now you could pick one up for $2000 or less ;)

13 hours ago, simbol said:

@AnkH

Interesting, what is your video card and what are your GPU's cores load when this is happening?

I use an overclocked 1080Ti currently. GPU load I did not monitor, as I am pretty sure that it will be around 99%, as I have solid 30-35FPS on the very same airport during daytime. Means: while I loose 50-70% of my FPS in LFMN when comparing daytime with night plus DL, I only loose 10-20% in LEBL. But as Rob stated, this is how it is as both sceneries come from different developers.

2 hours ago, Rob Ainscough said:

On the positive side, 5 years from now you could pick one up for $2000 or less ;)

Lol

If I am correct DL can be choosen at install or in the airport Config tool ( if it has one ).

And it has to be checked inside the P3D menu.

Anyone knows what happens framerate wise when DL is enabled in the airport , but disabled in the P3D menu ?

If it makes no difference with DL off then I will install all V4 airports with DL on ...

regards, Gerard

 

7 hours ago, GSalden said:

Anyone knows what happens framerate wise when DL is enabled in the airport , but disabled in the P3D menu ?

Yes, you don't see any DL specific lighting at the airport and no impact to FPS.  Pending airport developer this mis-match may look odd at night as the airport dev could be adjusting baked light textures when DL is or isn't enabled (via config tools or reading the prepar3d.cfg to determine ... i.e. something SODE could do) ... so it's not always just about the light types.

A more common approach for those FPS challenged and not willing to compromise AA levels, is to turn OFF airport DL per scenery configure tool provided by developer and keep DL enabled (at night/dawn/dusk) in P3D so you will at least get to see Aircraft lights working well, AI traffic lights working well, GSX vehicle lights working well, and still have the baked light textures for the airport.

Cheers, Rob.

EDIT: Of course you miss out on the wonderful DL at those airport designed to support it, and DL makes a huge difference at airports in terms of visuals, even more so if one has considerable AI traffic.  What I do is disable/enable DL per airport config based on how it performs for that airport ... note the size of the airport doesn't always make a difference, I've seen very small airports take a huge FPS hit with DL configured to enable via their config tool, and I've seen very large airports NOT take a huge hit with DL configured to enable per airport configuration.  

As my standard process, prior to any flight I plan, I do:

1.  Check DL performance at departure and destination airport
2.  Check no elevation conflicts at departure and destination airport
3.  Make sure GSX is working at both departure and destination airport
4.  Make sure I have AI traffic at both departure and destination airport

Since I usually like to fly from Day into Dusk/Night and Dawn into Day, I time my departure/arrival accordingly.

All good stuff from Rob.

I can say from experience with my system, latest versions of FlightBeam KDEN, KMSP, and KSFO, I have to turn DL off in FlightBeam Manager or my fps suffers considerably - low 20's or below...and that's while using 8x MSAA. Generally speaking, my system is not robust enough for airport DL. Depending on scenery, it can be touch-and-go with aircraft DL, at least when at the gate.

Rob, I also like to fly day-into-dusk...do you find that as the sim is transitioning into dusk or night, when you see each minor step into darker lighting that it creates a minor sim slowdown?

58 minutes ago, somiller said:

when you see each minor step into darker lighting that it creates a minor sim slowdown?

I haven't noticed that ... there is a slight pause shifting to dusk/night lights.  But once the sun is down, I usually switch to one of my night time graphics settings profiles (per my web site) as to ensure smooth FPS at my destination.  My Day time profiles have DL disabled and more shadow types enabled, my dusk/dawn/night profiles have DL enabled and less shadow types enabled (I don't have much of a need for shadows at night unless it's full moon).

I do however always run with TEXTURE_SIZE_EXP=10 which makes for a very nice distance viewing at all altitudes.

Cheers, Rob.

47 minutes ago, Rob Ainscough said:

But once the sun is down, I usually switch to one of my night time graphics settings profiles (per my web site) as to ensure smooth FPS at my destination.

What is your method of switching P3D setting profiles in-flight?

Thanks,

I wish P3D can dynamically switch certain features on/off depending on the time of day. Such as disabling shadows when not needed or dynamic lighting for certain objects when far away. This kind of dynamic optimization would result in much better performance.