OOMs & OOMs....&OOMs

Any issues, problems or troubleshooting topics related to the Prepar3D client application.
david roch
Posts: 18
Joined: Tue Sep 27, 2011 7:55 pm

Postby david roch » Thu Oct 09, 2014 2:29 pm

Another thing to check is VRAM usage ... I recall being in some NCA areas (KMRY I believe) where VRAM usage was very low (<1 GB) but VAS usage was very high 3.7GB starting. My normal VRAM usage is anywhere from 2.2GB to about 4.3GB ... so when I see my VRAM <1GB it makes me wonder if something is CPU bound rather than GPU bound.

I don't recall if Squamish was one of these areas, can check later. But a typical 2-4 hour flight in Orbx AU or Orbx NCA/PNW will consume about 600-700MB VAS and that includes using GSX at both departure and destination airports, and ASN, REX 4, and Aerosoft's A320, etc.

Also make sure you have Tessellation turned ON.

Cheers, Rob.

Posts: 9
Joined: Mon Nov 25, 2013 7:55 am

Postby airbenny » Thu Oct 09, 2014 2:53 pm

The same hir!

I really love P3Dv2, but the OOM makes me crazy.

P3Dv2 is a huge step in the future of FlightSim but we need a 64bit version.

So, I will also switch back to FS.

I come back after the release of the 64bit version

Thank you Lockheed Martin development Team for the grade work on P3D.

see you


Posts: 1173
Joined: Sun Sep 18, 2011 10:20 pm

Postby Kosta » Thu Oct 09, 2014 3:08 pm

Hi David,

Long time no see.

That is a quite decent PC, even for P3D quite good.

The OOM is unfortunately in P3D worse than it ever was in FSX. The reasons are I guess advanced graphics and everything new they packed in. At every time in any situation, P3D uses at least 200MB more VAS than in FSX.

64bit is really much needed, and is surely the only solution to this very known problem.

However, before we get that, I would rather see any memory leaks fixed. So my first question would be, do you see rise in VAS while doing steady flight without any addons? Because I flew the default sim with basic addons like global mesh, FTX global, vector and landclass for 12 hours, as a test, just over the globe, and my VAS remained almost the same. The aircraft was FSX 737, which I use for testing.

Posts: 103
Joined: Wed Nov 06, 2013 2:46 am

Postby DylanM » Thu Oct 09, 2014 3:16 pm

No OOMs here (even after 4+ hours of flight time between full ORBX regions). OOMs were, however, very regular occurrences in FSX (even after years of futile tweaking bufferpools and all that other nonsense).

Your PC is definitely capable and you have a better video card than I do (so you shouldn't be hitting any walls after 1/2 an hour). First things first - what exact addons are you using and what are you P3D settings? Do you have a vanilla install or are you using any tweaks / nvidia inspector settings?

I assume your PC is already optimized and no other apps are running in the backround.

Posts: 639
Joined: Fri Oct 15, 2010 8:38 pm

Postby vgbaron » Thu Oct 09, 2014 3:25 pm

Hi David - It's been a while. I haven't had an OOM in the last two versions but others have continued to report same. If you use FSUIPC you can set it up to display a running total of remaining VAS which might help tracking down the cause on your specific setup. Reducing various settings can help. Try setting a dedicated flight where you get an OOM and watch it in FSUIPC. Then drop your autogen and retest - perhaps you can isolate the cause.


Posts: 125
Joined: Mon Nov 25, 2013 3:15 am

Postby david.merak » Thu Oct 09, 2014 5:12 pm

No OOM´s here, only r6025 error every flight. in any time. lol.

Posts: 38
Joined: Wed Nov 27, 2013 2:35 pm

Postby sanh1977 » Thu Oct 09, 2014 5:24 pm

No OOMs here either. 64 bit not needed.

david roch
Posts: 18
Joined: Tue Sep 27, 2011 7:55 pm

Postby david roch » Thu Oct 09, 2014 5:32 pm

Hi Kosta, Hi Vic! :-)

Nice seeing you back guys!

Thanks for the good advices.

I'll check the VAS with FSUIPC(new version today BTW)and drop down the autogen this week end.

Thank you Dylan,

Actually I only fly in ORBX NA zones, FTX Global and with the Milvitz Baron.

Fresh and clean v2.4 install, vanilla cfg, no nvidia tweaks at all.

david roch
Posts: 18
Joined: Tue Sep 27, 2011 7:55 pm

Postby david roch » Thu Oct 09, 2014 7:01 pm

Great job Srdan, I've just fount your very helpful document


Thanks! ;-)

User avatar
Rob Ainscough
Posts: 2596
Joined: Sat Jan 05, 2013 6:46 pm
Location: Oregon USA

Postby Rob Ainscough » Thu Oct 09, 2014 8:13 pm

All my flights have been OOM free, but I carefully manage my graphics settings. I've done many Long Haul flights (over 4 hours) in the A320 and CS777 ... plenty of shorter flights (2 hours) in the A318/319 and L1011 using Orbx NCA + Vector + REX 4 + FSDT/FB airports + ASN, etc. etc.

Graphics settings I use: http://www.robainscough.com/P3D_V2.php

Some tips on how to avoid OOMs:

1. Don't switch aircraft within the same P3D session, goto departure location, pick your aircraft, save the flight, exit P3D, then double click the .fxml file to load (P3D should be associated with .fxml ... if not associate it) and do not go into the select Vehicle screen

2. Keep textures (all of them) at 1024

3. FTX Vector - disable secondary and tertiary roads and railways

4. Keep Building AutoGen at Normal unless you are in more remote areas (big cities like KSEA, KSFO will be impacted significantly by this value)

5. Keep terrain resolution at 15cm

6. Keep Scenery complexity at Very Dense or less (primarily to avoid overloading the GPU but does use a little less VAS)

7. Orbx NCA - I had to turn OFF some BGL's (rename extention to .OFF) that were problematic and caused OOMs, they are:






8. FTX Global, make sure you're on version 1.3

9. Make sure you have the latest P3DV2.x Orbx Libraries ...140927

10. Manage your views ... on the heavy VAS aircraft/locations I stick to just VC and Spot.

Hope that helps ... I'm not saying there are problems with the Orbx NCA .BGLs ... it just helped reduce VAS usage and improve performance with no huge noticeable visual difference.

Cheers, Rob.
Rob Ainscough

Posts: 77
Joined: Thu Jan 03, 2013 7:32 am

Postby mta00jtl » Thu Oct 09, 2014 11:41 pm

David - I am in the same boat as you and trying to manage VAS really carefully. I have mentioned on a couple of posts before that VAS usage in 2.3 and now 2.4 does seem to be much higher. I'm not sure what has been changed to cause this but suspect we are starting to really reach the limits of what an older 32 bit application can handle following the improvement in graphics and coding that LM that has brought to P3D. P3D 2.4 looks and performs amazingly but I suspect the cost for this, if you use lots of adds on (e.g. Orbx, FSDT, Airbus A318/319), is VAS based. That said, FSX has the OOM's too. I certainly prefer P3D stability and the occasional OOM to FSX non-stability (for me anyway) and the more frequent OOM! If you want to cling to some hope then take a look at PMDG's update regarding P3D where I think they mention a forward looking study into a 64 bit future...who knows what this could mean but I am optimistically hoping that they are preparing for a (relatively) near future 64 bit release - near future for me would be anywhere in the next couple of years!!

Rob has provided some excellent tips above which I am going to try and follow myself - thanks Rob as always!


Posts: 1173
Joined: Sun Sep 18, 2011 10:20 pm

Postby Kosta » Thu Oct 09, 2014 11:59 pm


Quote from david roch on October 9, 2014, 19:01

Great job Srdan, I've just fount your very helpful document


Thanks! ;-)

Many thanks. ;-) They all explain the one and the same thing!

It comes down to what addons you use and how much you load into the sim. There have been memory leaks and really high VAS usages in previous versions, but in v2.4 that is supposedly fixed.

Posts: 31
Joined: Fri Nov 29, 2013 4:05 pm

Postby domkle » Fri Oct 10, 2014 2:55 am

Not a single OOM after 6 weeks of intensive use of 2.3 then 2.4 with A2A Accusim birds (Cherokee, P-40, P51) in OrbX fat regions and converted airports with OPUS weather. Autogen at dense. Textures 2048. No FSUIPC. One to two hour flights.

i4770 @4.5 + O/C 780Ti @2560*1440. Windows 7.


Prepar3D v3.3. on a 4770 @ 4.4 GHz and a 1080 @ 2560*1440 - Warthog HOTAS and CH pedals

david roch
Posts: 18
Joined: Tue Sep 27, 2011 7:55 pm

Postby david roch » Fri Oct 10, 2014 9:52 am

Rob, thanks a lot for your helpful and brillant answer.

Plenty of good things to know and others to avoid!

Thank you James, I'm eagerly awaiting for the PMDG birds to be compatible and who knows, a x64 version would be indeed fantastic! :-)

Folks, I really appreciate your help and inputs!

Kindest regards,


Posts: 1173
Joined: Sun Sep 18, 2011 10:20 pm

Postby Kosta » Fri Oct 10, 2014 5:16 pm

Well, David, I was doing some OOM testing on v2.4, and I can confirm that there is a big in-flight load, in which the sim still doesn't release the memory.

I started in LGKR, flying HDG320, 10,000ft, default 737 from FSX on Autopilot. The loaded flight was about 1600MB, and this is with full mesh, FTX global, vector and LC. I left it flying for 3 hours and came back. The VAS load was 2400MB. 800MB load was just through the flight. I'll do a similar test in FSX to compare.

Return to “Prepar3D Client Application Questions”

Who is online

Users browsing this forum: Google [Bot] and 106 guests