There seemed to be a need for me to reiterate what is already known and accepted within the flightsim community about those so-called “OOMS”, so here it is.
A number of our group members recently suffered catastrophic OOMS whilst flying lengthy online flights. An inevitable discussion generally follows any such mishaps, and these usually covered the usual gamut of rumours and myths of how to fix OOMS, including the emptying of Windows Recycle Bins, changing the values of the Windows SWAP file, clearing out temp files, and so on.
FSX and P3D V1-3 Out of Memory Errors (OOMS) are a recurring and clearly misunderstood problem affecting keen flight simulation enthusiasts. These strike with little warning and they have absolutely no appeal - there is no recovery from this error, and you will be going down.
Happily, there is a way to banish OOMS from your flight simulation immersion, so read on. However, know now that you might not like it.
In the beginning, 32-bit Operating Systems and 32-bit applications were the norm as 64-bit architecture wasn’t yet a thing. The hardware requirements for flight simulation back then were very different to what they are today, but nevertheless they were still pretty demanding for the time. It seems a bit obvious stating that you couldn't run a modern 64-bit flight simulator on an old 32-bit version of Windows running on an old PC system because put simply, you cannot, and that's because a square 64-bit peg won't fit into a round 32-bit hole, not even if you bash it into place.
The converse, however, is true. A 32-bit flight simulator can be run on modern hardware featuring an up-to-date 64-bit operating system, and flight simmers do this all the time with their 32-bit FSX or P3D V1-3 running under Windows 10 or Windows 7 64-bit.
If course it’s not just about the software, as the hardware requirements of our old flight sims are very different to the exacting needs of our concurrent flightsim platform. The difference is like night and day.
One of my favourite 1999 period flights sims was Flight Unlimited (I, II and III), but it carried back then the sort of taxing hardware levy that many of today’s top end games feature, meaning that you needed a top tier PC to run FUIII (plus a costly Voodoo FX graphics card). Today, FUIII will run quite happily with all sliders maxed out on a ten year old Intel Atom powered 1Gb RAM netbook.
The real problem is this; 32-bit applications can address an absolute, categoric, and finite maximum of 4Gb Virtual Address Space (VAS) and there is no evading this principle, period. VAS is a very different entity to memory (RAM) or swap files (effectively HD space), and it is to do with PC architechture.
Think of VAS as a Post-it Note whereby 4Gb VAS would equate to one of those tiny 1” square Post-it Notes. Once you have written, scribbled, and drawn all over it, it then becomes full in the same way that a glass is full when it begins to overflow. You’ll not get another drop in it.
OK, so now you wisely reach for a rubber, ink eraser, or Tipp-Ex in order to rub out some of those notations in order to make space for some more. However, whilst your theory is sound, it doesn't quite match the reality of the situation. Simply, you cannot free FSX or P3D V1-3 filled VAS in this way.
Back in 2006 when FSX was shiny and new, unlike the then mature product FS2004 (FS9), you had necessarily to wait a while before add-ons began to appear in the form of freeware or payware scenery, aircraft, weather packages, and so on.
What you got was a capable top-end flight simulator, and once add-ons began to appear, they appeared in droves! In fact, the market grew enormously as demand for better aircraft, scenery, weather packages, and utilities grew into the FS market that we recognise today.
However, what didn't change with the market growth was the simulator platform itself. Despite two early MS Service Packs, and an early refresh in the form of MS FSX Acceleration, nothing in the chemistry of the simulator changed to keep pace with hardware or operating systems. Beneath the many expensive add-on high resolution textures, intricate and complex study-level aircraft, and detailed scenery areas, the platform itself remained unchanged in both essence and form, steadfastly fastened to its unchanged 32-bit code.
Even the PCs that run our legacy FSX or P3D V1-3 platforms are today better, faster, and more potent than ever before, sporting overcloked multi-core CPUs and GPUs capable of handling 4K textures without ever breaking into a sweat.
It is akin to superficially decorating a house whilst ignoring any serious underlying flaws and defects.
Going back to my Post-it Note analogy and the impossible theoretical rubbing out of some scribbles to free up VAS begins to have an important bearing on performance.
When FSX was in its infancy, no-one quite anticipated how the software and hardware markets would grow, or how long FSX would be used as the most popular flightsim platform ever. Its code was remarkably without mechanism to clear from VAS what had been used. You can fly default FSX from place to place to place practically ad-infinitum without an OOMS in sight, but you cannot fly a fully laden FSX festooned with bells and whistles from place to place to place without jeopardising your meticulously planned flight with the OOMS of gloom.
That tiny tiny Post-it Note of yours is inexorably filling up, and with it you detect a faltering and stuttering effect within the simulator itself as the FPS bleed-off toward single figures. This signifies that your flight will soon be ending prematurely. Let’s take a closer look at you flight.
Your takeoff was from a detailed payware airport under the skies of an intensely realistic weather system beautifully portrayed by a complex weather add-on. Your aircraft is a complex study-level model which sucks up every last drop of FPS performance. You fly away from the departure airport over glorious payware land class filled with autogen overlaying some astonishing mesh. Quietly in the background, processes have been shovelling data one way onto your 4Gb allocation of VAS. They haven’t been shy; they’ve been doing this by the bucketload.
Continuing onwards with you flight, you enjoy realistic weather fronts in detailed 4K texturing over 1cm per pixel scenery.
Perhaps you have flown for eight hours across the Atlantic or maybe it has been a short commuter hop, but you are fast approaching your destination just as a fully replicated city scene complete skyscrapers and multiple terminal area airports all busy with AI traffic comes into view.
Well, I'm sure that you get the picture and the message - your VAS is all used up.
What happens next is a shudder, a drop in FPS to single digits, a ten second freeze, and Bang!, you see the message that your computer has run out of available memory (not RAM, the culprit is the lack of VAS).
There are several VAS monitors that can show you how your VAS is being vacuumed up by your system; it’s just a read-only dynamic figure that is displayed somewhere. The way to think about VAS monitors is to liken them an aeroplane's fuel gauge. Whilst airborne, you can but watch the gauge as its needle moves towards empty, and you can do nothing about it until you have touched down and reset.
Whilst all flight simulators allow you to create and save situations, usually a specified aircraft type sitting on the apron of a particular airport, some complex aircraft will actually allow you to save situations whilst airborne. Thus, if your VAS is running low, you could try saving your flight to later restart where you left off. However, few aircraft support this midair feature as most will plummet if spawned high up off in the mid-Pacific. The theory is that if you restart midway, you’ll be starting with more free VAS.
If you would like to know more about VAS monitors, then take a look at my 14/09/2016 blog report "Pain in the VAS - Much Pain, Much Gain". Today, I’d change the title to "Pain in the VAS - Much Pain, Little Gain" because these days we have something that we didn’t have before.
If you are suffering from OOMS, ask yourself whether a fix is worth your while, or whether you don't mind having FSX or P3D V1-3 crash at the end of a long and meticulously planned and flown flight.
It’s perhaps worth mentioning that LM's P3D V3 attempted to address the inability of the ESP flightsim platform to liberate used VAS as your flight progresses by adding just such as feature. However, the jury is still out on how effective their system was. The truth, however, is that P3D V3 remains a 32-bit and is still subject to a macimum VAS allocation of 4Gb.
The fix is simple, but it carries with it great cost.
in order to forevermore avoid OOMS, and just ask anyone who has since chosen this path to flightsim salvation whether the fix works, all you have to do is retire your 32-bit platforms such as FSX or P3D V1-3, and move into the new era of 64-bit flight simulators such as X-Plane 10/11 or P3D4/5 where OOMS are but a distant yet troubling memory.
Referring back to my analogy of Post-it Notes for VAS, here is an approximate depiction of a 32-bit Post-it compared to a 64-bit Post-it Note (TBH, this doesn't do 64-bit much justice as I wouldn’t really have been unable to fit an accurate rendition of a true 64-bit sized Post-it Note onto the page!)...
That's it. Now go hide your FSX & P3D V1-3 and with it some of you older add-ons. They have served you faithfully for a very long time, but they are tired and so are you (of OOMS). Next, immediately take the plunge and move into the modern 64-bit flight simulator world, and finally consign those OOMS to the darkside of FS history.
Pass Go!, pay your $200, and move on.
You can pick-up some quality aircraft and/or scenery add-ons cheaply or even for free during our period of Coronavirus quarantine, as well as some great cost-effective airliners from QualityWings such as their BAe 146 & Boeing B757 Collections for a few Dollars apiece.
Should you chose XP11, then you can download the highly acclaimed Zibo Mod Boeing 737-800 (plus 737-700/900 Ultimates) totally for free.
There has never been a better time for flight simulation, if you know what I mean!
