FSX, Win7 64b and OOM (again)

[daveyd]

Hi Paxx,
Based on the information provided above, have you tried using Windows7's default Video Drivers?

Windows Display Driver Model (WDDM)

[Paxx]

UPDATE

Well it has happened again. In fact I have found a way to reproduce this OOM error consistently now. Other than a few (3, maybe) scenarios, FSX and the add-ons I have, all run flawlessly. This post is just an update to this thread for my own reference mostly. Interested folks can of course chime in and I welcome it.

The set of conditions I have discovered that recreate the OOM error for me are as follows.

Aircraft - Eaglesoft Diamond DA 42.
This is an excellent add-on aircraft. I in no way wish to besmirch this fine aircraft or the development group that put it together. I don't think this aircraft has anything to do with my OOM error other than putting a typical aircraft load on the system. It is simply the aircraft I was using when I discovered these set of conditions and was able to repeat them on demand. Again, I would heartily recommend this aircraft for anyone that desires a modern design, material and avionics twin for GA flying.

The Flight Plan.
Beginning at Northeast Philadelphia (KPNE) with a NE heading of about 50 degrees toward New York City. This brings UTX, GTX, Aerosoft Manhattan X, REX (real weather), several large busy airports (KJFK, KLGA, KEWR, KPHL), busy major highways with traffic, and a lot of passing AI air traffic into play as far as memory usage is concerned.

The Method.
When beginning the flight on my system total RAM usage is about 45% (as reported via a G15 keyboard, I fly full screen, two monitors). Freshly rebooted Win 7 uses about 22% on my system.

After take-off and heading towards NYC I fly the AP at 2000ft. I fly as normal except I load different views (A/S key on my system) a lot more than usual. This is to get all those textures and camera views loaded. I also monitor ATC Center to load some sound files. I also put gauge popups on the second monitor - all of them for this aircraft and test. This gets me up to about 65% RAM usage by the time I pass over Trenton.

As I approach NYC and the entities listed above come into play my RAM usage climbs to around 80%. Reaching Manhattan it approaches 90% and shortly thereafter crashes. I might have to circle the Statue of Liberty a few times, spam views but eventually FSX will crash every time with this message.



Surprisingly FPS remains pretty stable (about 22) even in this high RAM usage state.
And this is what the Task Manager Resource Monitor has to say about it before I close FSX out (the OS never crashes).



The system works fine when FSX reaches this OOM state. I actually made those screen shots with Photoshop and uploaded them while FSX was in a crashed state.

Just food for thought and I welcome anyone else who has had an OOM error on 64 bit Vista or Win 7 to share their experience.

[loki]

Have you noticed any similar memory increase while running other games?

[Paxx]

None.
Other games include;
FS9
Company of Heroes
Dragon Age
Crysis
COD4
Rise of Flight
Need for Speed: Shift
Empire: Total War
WoW
EQ
SCII
etc.


At most they hit about 50%+/- as reported by the G15.

I should note that flying from KJFK in the same aircraft towards and around NYC for hours doesn't result in a crash.

[loki]

That sounds like a memory leak in FSX or one of the add-ons you have installed. Have you tried the same route with a different plane yet, maybe one of the original FSX aircraft?

[Paxx]

Well I just discovered this yesterday so testing atm is limited. I have repeated it four times as described above so far. I understand these are extreme conditions/parameters (most don't intentionally seek the OOM error ) and I will test further in the coming days.

I just find it interesting that FSX 'thinks' the system is out of RAM with large address aware flagged and miles of RAM (virtual anyway) available.

[loki]

It probably has to do with the way FSX requests and accesses the address space. From the OOM article in the wiki:

This next bit of information is critical to coming to a more full understanding of what is causing the "OOM Error" to occur:
FSX will only use "contiguous 1MB blocks of VAS."
Anytime FSX cannot find a 1MB block of VAS in which to "load stuff," it will summarily crash to desktop...

http://www.flightsim.com/fswiki/index.php/OOM_Error

If something is filling up the address space with junk that shouldn't be there, the system will get to a point that it can't provide the address blocks that FSX requests. And while the address space available under 64 bit Windows is 16GB or larger (depending on the version being used), the system only has so much RAM to back up the address space. If the system has to start heavily swapping data to the page file, it may be able to respond to the requests quickly enough.

[Paxx]

I suspect you are correct. Specifically the "contiguous 1MB blocks of VAS" part.

Unfortunately for me, OS/application memory management programming techniques are not one of my strong points, so at this point I really can't come up with a more accurate guess.

Watching an i7 system, well cooled, 'take it in the face' is fun anyway. The FS series has never failed to tax whatever system I have had for the past 15 years or so.


*Edit - Re: "while the address space available under 64 bit Windows is 16GB or larger (depending on the version being used)".
I'm on W7 Ultimate 64b so 192GB.
Swap File is managed by the OS (currently about the same as last November 6000MB +/-).

[Paxx]

Further Testing.

Once again I in no way wish to detract from the quality of these aircraft/scenery/add-ons. I consider all of the payware discussed here to be about the best there is for FSX and the people who bring us these products are in my opinion the best in the business. All of these aircraft are installed correctly and have given me zero trouble generally speaking. I fly them regularly all over the world, long flights and short flights with nary a problem except in very few situations.

I flew 6 aircraft, each twice, generally following the flight path as described above. I kept airspeed to 200 kts on the AP. I rebooted the system between test flights.

FSX Default 747 - OOM error x2.
Took a little longer but about three laps around Manhattan, extensive view switching/panning and OOM. RAM usage hit 93% before OOM both times.

FSX Default 737 - No OOM error x2.
I flew this aircraft for about 40 minutes. Reported RAM usage never rose above 81%. Frame rates good, flight as normal, no spikes or blurry textures. I didn't see it OOM'ing, so I ended the flight and then FSX experiences a "Fatal Error" while trying to load the aircraft at the Free Flight screen. FSX also rebooted itself (NOT the OS) at this time and all was happy again RAM-wise...about 32%, which is typical for me at the Free Flight screen. Second flight was about the same (only half an hour) with no fatalities at the end. /whew.

FSX default Lear 45 - OOM error x2
OMM'ed at a reported 88% and 91%. I had to circle Manhattan once, each time.

Wilco 737 PIC X - OOM error x2.
Pretty much exactly as the Diamond DA 42. Yes I am aware of the Wilco 64 bit disclaimer.

Flight1 Cessna Mustang for FSX - OOM error x2.
Kinda expected this one. Same as Diamond.

PMDG 747 400 X - OOM error x2.
Pretty much exactly as the Diamond DA 42.

About the only quirky thing I do FSX setup/config wise that most probably don't is that I use a batch file with this in it to start FSX.

start /high fsx.exe

It is my opinion that this doesn't create any noticeable FSX performance improvement, but this is my homage to the old Boot Disk routine from yesteryear. It certainly doesn't hurt anything that I am aware of.

*Note - The 747's were flown with a full center tank only. I had to lighten the load in order to launch at KPNE.

[loki]

Now that you've identified that it happens consistently with different aircraft, what about a different route of similar length? Or maybe two routes, one with a large detailed city at the end of the flight, and one to somewhere like, say, Inuvik (CYEV)?