[Bug] Graphics Memory Leak??

[Keller5678]

Using Prepar3D v3.4 + HF3 on Windows 10 x64

On long haul flights I prefer to minimize P3D and let it run in the background, the sim is set to pause at TOD
This has the benefit of reducing GPU usage to 0% and therefore lower power draw.

However whenever I maximize the window and rejoin the sim at TOD, the frame rate has drastically dropped from 33 fps to roughly 20 fps. Also the GPU usage shoots to 100% where it normally should be running at a max of 70-80%. See the picture below (note the top graph shows GPU usage):



Furthermore, disabling weather and clouds in the exact same situation, does nothing. The GPU usage is stuck at 100%, yet there hardly any graphics to process??? :





Lastly, to be certain that this is a bug. I ran the same scenario (i.e. same plane, flight from EGLL to OMDB @ same departure time), but this time I DID NOT minimize prepar3d and let it run through to TOD. The framerate at still at a solid 32 fps, GPU usage remains normal 70%, and the VAS usage is also better:




Things I have tried, but with no success:

• Disabling all addons
• Different weather engine and no weather at all
• I do not use SGSS ever
• Different aircraft
• Nvidia Driver from Dec 2016 v376.33

Can anyone else recreate my issue? Im certain it is a bug...

Cheers.

[Martyson]

"Things I have tried, but with no success:

Disabling all addons
Different weather engine and no weather at all
I do not use SGSS ever
Different aircraft
Nvidia Driver from Dec 2016 v376.33"


Did you try with Default weather and fly the whole flight in a default P3D jet ?

[Keller5678]

Did you try with Default weather and fly the whole flight in a default P3D jet ?

Yeah I tried with default weather (clear skies), still the same issue, must not be related to clouds.

In fact with further testing I found a solution. Add the following to the prepar3d.cfg:

[BUFFERPOOLS]
UsePools=0

I thought this tweak had become obsolete, but it still works?? And I have improved overall VAS usage as well! It must be something to do with the graphic processing.

Google says

Hailed by some as the holy grail of tweaks, this setting basically instructs FSX not to reserve any video memory.

Maybe some of the devs can enlighten us

[Martyson]

I do not have [BUFFERPOOLS] and I do not have problems.

[Keller5678]

I do not have [BUFFERPOOLS] and I do not have problems.

Have you tried running P3D minimized for a long haul flight?

[Martyson]

I do not have [BUFFERPOOLS] and I do not have problems.

Have you tried running P3D minimized for a long haul flight?

No, I do not run P3D minimized for a long haul flights.
I do not minimize a flight except while troubleshooting.

I seldom do long haul flights.

I do not set Pause at TOD and go to bed. I fly the entire flight.

I do not do other internet activities during a flight (e.g., no videos or searches).

Did you try with Default weather
and fly the whole flight in a default P3D jet ?
The reason I ask was to verify your problem was not do to a 3rd party aircraft or weather engine before other pilots start doing a long haul / P3D minimized tests to verify your reported bug.

[Keller5678]

Yes I have tried it with default weather, still the same problem

Regarding aircraft: I haven't been able to try with the default aircraft because none of them can really fly intercontinental (i.e. long-haul), but I did try it with a different 3rd party aircraft which produces the same problem.


.

[Martyson]

"Regarding aircraft: I haven't been able to try with the default aircraft because none of them can really fly intercontinental (i.e. long-haul),"

Just wondering, why not?

[Keller5678]

.
So it turns out my Buffepools tweak did not fix anything.

I tried using the default aircraft - Beech Baron 58. Setup a flight from EGLL to OMDB with Clear Skies. Set 'unlimited fuel' in the realism settings to make the flight possible. Got it to cruise and let P3D v3 run minimized.

Maximized P3D nearing OMDB and same problem! Graphics usage fixed at 100% and low 20fps with major stuttering:





Tried without minimizing P3D and now it works normally:





What is going on?????

[Martyson]

What I would do as a test with clear skies and default P3D aircraft:

Minimize for 10 minutes then maximize it and do your readings / screenshots.
Keep doing this every 10 minutes during a long haul flight to find out when the problem happens.

Do the the same flight / test again and see if it happens at the same time (repeatable).

[Keller5678]

Doing that will ensure the problem doesn't happen,

The supposed leak happens only if P3D is kept continuously minimized for a prolonged time (i.e. long haul flight)

[Kosta]

Never minimize, texture loading bogs down, doesn't happen etc. Just leave running in the background, that is enough.

[Keller5678]

Never minimize, texture loading bogs down, doesn't happen etc. Just leave running in the background, that is enough.

Surely Kosta, that must mean it is a bug? Even if texture loading slows, it should return to normal when re-maximized and flush the old textures. The reason I minimize, is to bring GPU usage down to 0% whilst cruising to reduce power draw and heat production

[Kosta]

Never minimize, texture loading bogs down, doesn't happen etc. Just leave running in the background, that is enough.

Surely Kosta, that must mean it is a bug? Even if texture loading slows, it should return to normal when re-maximized and flush the old textures. The reason I minimize, is to bring GPU usage down to 0% whilst cruising to reduce power draw and heat production

I don't think so. This is typical for windows, not P3D's fault. Applications in the foreground will get more "attention" than those in the background. So does texture loading, P3D stops loading all of texture, but I think it also stops releasing. After you pull it up, the effect is no different than using refresh scenery function (P3D loads everything new).
While I respect that you want to reduce power dran and heat production, I don't think that what you want is possible. Games are meant to be running in the foreground, and the ones I have, if I minimize to the background, the resources are still being used and GPU is always the same (example is Elite:Dangerous).
The only thing P3D is doing wrong actually is not using the resources while minimized, and that should be corrected IMO. So that I can really minimize it, but it still performs the same as being open.

[craig1231]

I too think there is a problem when minimising the window. On one flight, I barely minimised the window and landed with about 30 FPS. I left the P3D window minimised for about 30 mins and when I re-opened the window the FPS had dropped to 20.

I'll have to see if it is reproduce-able, because at the moment I don't know if it is. But my findings seem very similar to what Keller5678 has found. I shall do some more testing.

But at least my P3D doesn't crash any more. I was plagued with P3D crashes since version 3.4. Version 3.4 has been the WORST version released in P3D's history, it is absolutely plagued with bugs and unfortunately it is damaging LM's reputation especially for the up-coming version 4.