FPS slump on approach

[xkoote 57]

Damn, was just about to post about this. I have been testing my bum off at OMDB. Don't know if more airports are affected. Every 5-7 seconds BAM, a drop in FPS. What frustrates me is that when not in stutter mode, I get more than double the FPS, so I KNOW the system can take it. What I also noticed is that:

 

the stutter slows down the SIM. In other words, it is not a simple drop in frame rates for me. But I actually cover less ground during the stutter. You would expect to cover the same amount of ground whatever the FPS. (Only the distance covered per frame would change) But not here. Say I'm on final at FlyTampa Dubai. I can visibly see the plane kind of "slowing down" over the ground, then "accelerate" (actually not accelerating, but returning to normal FPS), then after 5-7 seconds again.... It's like I'm driving my car while braking and throttling. Very very strange.......

 

Again, the most frustrating part is that when the stutter isn't active, I get double the FPS. The ONLY way I could eliminate it at OMDB is to turn down all sliders related to mesh, texture etc etc. FXAA, AA, Sampling, water detail (at least up to high) did not trigger the stutter. But as soon as I crank 1 or 2 of those sliders above min......it comes back.

[Sino 0]

My 2 cents:

 

I would look to check if it is something related to your ground scenery; when you pitch down for the approach the ground area that you are looking to is really big and demanding compared to other flight phases (i.e. in climb you are looking to the sky - not much to load for the system)

 

For this reason I would try to lower all the "scenery" settings (Level of detail, tesselation, mesh&texture resolution, scenery complexity, autogens... and shadows as well). See if it changes and then start to increase the settings accordingly to required performance.

[glider1 90]

 

 

I can visibly see the plane kind of "slowing down" over the ground, then "accelerate" (actually not accelerating, but returning to normal FPS), then after 5-7 seconds again.... It's like I'm driving my car while braking and throttling. Very very strange.......

 

That sounds like you have the sim set to unlimited frame rate but can't maintain VSYNC lock. You are locking the FPS in the sim?

[xkoote 57]

Glider1,

 

I either have my framerate set to unlimited or 20. I have tried the two of them. I have also tried turning VSync on and OFF, but don't know exactly how it works.

 

Say with my setup and flying in Dubai, I get 18 to 25 fps (which I am comfortable with) depending on time of day, spot or cockpit etc etc. What would be the best setup? VSync on? Off? Frames unlimited? Or how many?

 

Thanks in advance for your help. I'll try reading up on the VSYNC to framerate question as well but would appreciate your input.

 

 

Cheers,

[glider1 90]

 

 

Say with my setup and flying in Dubai, I get 18 to 25 fps (which I am comfortable with) depending on time of day, spot or cockpit etc etc. What would be the best setup? VSync on? Off? Frames unlimited? Or how many?

 

When the FPS is that low, you can't get the simulator smooth there isn't enough headroom. You could try the radical approach of locking to 15FPS which is a multiple of 60HZ monitor refresh, then enable VSYNC and triple buffer. At least 15FPS would give you 3 FPS of head room above your 18FPS minimum. You need headroom when you want to get the simulator smooth.

[Guest]

IMO, This is a performance hit plane and simple! The demand on the sim during final approach and landing is crushing. All other phases of flight are not so hard on performance. That's it, Nothing to do except wait :smile:

[Guest]

Has anyone with this problem updated to Prepar3d V3.3 yet? And if so have you seen the same loss of FPS on approach is it cured?

[iamlmc 2]

Has anyone with this problem updated to Prepar3d V3.3 yet? And if so have you seen the same loss of FPS on approach is it cured?

 

I am very curious about this as well!

[Afterburner 374]

My initial test with P3D v3.3 has revealed that the FPS seem to be better during approach. I have noticed that there are fewer sporadic FPS drops that occur on final approach.

 

To give you an example: A while ago I created the following video (link is below), where I documented the FPS drop on approach in FSX and Prepar3D during a circle flight from and to KORD. In the video, I used version 3.2. With everything activated in ORBX vector, you can see that the FPS fluctuate relatively widely on approach, dropping below 20 relatively frequently. On a recent test under the same situation with the same settings using v3.3, I had relatively stable 22-23fps on final approach (just a few seconds before touchdown), and it turned out that refreshing the scenery (as done in the video with the other sims) was no longer necessary to boost the FPS after landing. I would need to do some more tests to arrive at a final conclusion, but for me, the difference was noticeable. (By the way, the VAS consumption was a little higher in 3.3 compared to 3.2 for me, but only by ca. 50 MB.)  Yet I'm also waiting for the announced hotfix, because I would not update if that breaks the compatibility with some older airport add-ons.

 

 

[Guest]

Sounds promising nut my minimum requirement in all scenarios and at all times is 30fps. If I cannot maintain 30fps at 30hz at all times I am done with Flight Sim. In fact I am done with flight sim until that is a reality already. Sounds demanding I know but for years I dealt with the frustration of stutters in Flight Sim until I discovered the 30fps at 30hz solution and its beautiful! But as I see it is impossible to maintain over 30fps on approach on setting that I find acceptable. In fact I think it is impossible all together on any setting ion a large hub in an urban area. I understand that even if I upgraded to 2 GTX1080's in SLI, I still couldn't do it. Call me picky but I am done with it until this becomes a reality. Probably won't be long though!

[iamlmc 2]

Sounds promising nut my minimum requirement in all scenarios and at all times is 30fps. If I cannot maintain 30fps at 30hz at all times I am done with Flight Sim. In fact I am done with flight sim until that is a reality already. Sounds demanding I know but for years I dealt with the frustration of stutters in Flight Sim until I discovered the 30fps at 30hz solution and its beautiful! But as I see it is impossible to maintain over 30fps on approach on setting that I find acceptable. In fact I think it is impossible all together on any setting ion a large hub in an urban area. I understand that even if I upgraded to 2 GTX1080's in SLI, I still couldn't do it. Call me picky but I am done with it until this becomes a reality. Probably won't be long though!

 

I do understand what you're saying, I myself suffer from some type of "OCD issues" regarding this problem. But I have found, regarding Prepar3D, that it is more a matter of smoothness than to achieve a fixed FPS minimum. Although with all the bells and whistles and the various addons it's more easy to say than done!

 

PS: Thanks for the inputs Afterburner.

[Afterburner 374]

If you want to maintain 30fps at all times, you need to manage your graphics settings properly. In my video, I used very high scenery settings with a ton of AI and ground traffic at a very busy airport (while having everything turned on in ORBX Vector).

 

@iamlmc  You're welcome!

[Midnight Music 252]

I've been trying to chase the cause of the FPS slump on approach since 3.2. I have tried everything, shutting off ai, shutting off ASN and trying different aircraft. Finally in 3.3 I have made some small headway to reducing the problem by bringing my Autogen slider down a notch. I have a decent rig, an i7 4770k oc to 4.4 and a 980ti, but by moving Autogen from Very Dense to Dense I do see a lessening of the FPS slump, especially in 3.3. The sim still looks great, there's still plenty of tress which is all I want.

 

I'd really like to hear from others what your thoughts about this might be.

[Afterburner 374]

I made some more tests, and unfortunately, I have to retract my above statement; updating to ORBX Central V2.1 and initiating the migration process into a unified lclookup messed up the roads (they weren't depicted), which caused FPS to go up slightly in my yesterday's test. I noticed the issue with the roads today. After sorting out that issue and performing another test flight, there was no benefit in FPS over v3.2 on approach. Sorry for the confusion.