Mark & fellow simmersWith my recient upgrades my FS9 has improved... Great!FSX is still out of the question. So much so I uninstalled it last night!So what is this: userva swtiches (where userva = system ram - 768Mb - video ram; otherwise excessive paging will occur)Don't recall that but dropping the complexity to 95% helped.JerryEQ:AMD Phenom 9550ATI 8400 w/ 5123GB Ram

Mack what do you mean by /3GB switch enabled ? Where can I find it and howcan I do that?Al

Mack what do you mean by /3GB switch enabled ? Where can I find it and howcan I do that?Al

The reason FS9 craps out with OOM errors (which manifest themselves either with the dreaded OOM message box or much more often with just a black screen CTD) is because it busts through its limit of 2Gb virtual memory for user files (32bit OSes are limited to 4Gb virtual memory space, 2Gb for the kernel and 2Gb for software). What the /3GB swtich (in boot.ini) does is allow software to use 3Gb of virtual memory at the expense of kernel space. What /userva does is give some of that memory back to the operating system (which it really needs!), by fine tuning how much memory is allocated to the user virtual address space. For example, in my system, I have 4Gb of RAM, with a 9800GX2 gfx card (512+512=1Gb of memory). Since the OS maps the gfx memory to the address space, this memory has to be accounted for when fine tuning the userva allocation and it is done via the rough calculation that I mentioned in my previous post, that is, for my example: 4096 (total) - 768 (for the OS) - 1024 (for the gfx card) = 2304 Mb for apps. An incorrect userva setting can, at its least, cause significant paging and erratic texture loading behaviour and at its worst, create significant instability. FWIW, I haven't had any problems, but YMMV.Of course, to take advantage of the increased user space via the /3GB and /userva switches, FS9.exe has to be patched to make it large address aware (the patch is on the net somewhere, you can find it via google).Hope at least some of this made sense.Here's an excerpt from my boot.ini so you can see what it looks like once set up (you may or may not have additional switches in there):[boot loader]timeout=30default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS[operating systems]multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=alwaysoff /fastdetectmulti(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional 3GB patch 2304" /noexecute=alwaysoff /fastdetect /3GB /Userva=2304Also, as a word of warning, should you decide to mess around with boot.ini, make sure you set it up like I have above in order to have a "safe" config to fall back on should something go wrong :)

I tried that and still same problem on long flight to an airport with nice pay scenery like aerosoft.Any other suggestion? I am getting frustrated.ThanksAl

I tried that and still same problem on long flight to an airport with nice pay scenery like aerosoft.Any other suggestion? I am getting frustrated.ThanksAl

Okay!!So if what I have read is correct you have done all that has been suggested and you are still having problemsBefore you start down the road of trouble shooting which is a PITA Have a little look in your addon scenery files or any scenery file that you have added and see if there are any empty texture folders.What is worth a try is to turn off 50% of your Add on scenerys and try a flight that you know will give you an OOM If you still get one at least you know it is not that 50% of your add on scenery :( It is a tedius job and at times it seems it would be quicker just to re install BUT if you go down that road you may install the same problematic addon again .There are several recent posts about this problem and good ideas about trouble shooting them.The short answer is , there is no short answer , I guess your left with trouble shoot or a 64bit OSMark

Thanks Mark, will try that.Al

Mark I feel stupid to ask you that but howcan I bring the add on at 50%?Thanks man.Al

Mark I feel stupid to ask you that but howcan I bring the add on at 50%?Thanks man.Al

It is not stupid to ask it is stupid not to!At the main menu click on settings (bottom left coloumn )Then click on Scenery library you should now see a window with all your sceneries .next to them is a box with a red tick mark un tick any scenery you wish to de activate and then re start MSFS You can re activate them by just ticking the box again but you will have to restart the simAny problems let us know Mark

Maybe I'm just not understanding this but I think the solution is right there in front of you. I've read all these people getting OOM errors and the one thing in common is there running 3 or more gig of memory on a 32 bit system.I'm running FS9 on a buisness laptop (with quite a bit of other apps including Norton Antivirus etc) which shares its memory with the video card (on board video) and I can run the PMDG 747 and MD-11 on 10-12 hours realtime flights without an OOM. This laptop only has 2 gig memory. (Granted I'm not crazy about addon scenery; tried freeware Boston, very nice, and I got the only crash in FS I've ever had with this laptop; think that was AES so got rid of it also, so I have none and only use Ultimate Terrain, Activesky and Radar Contact)I would say take your system down to 2 gig of memory and see if you still get OOM errors. If 32 bit systems and FS9 and XP don't handle 3 gig of memory very well why use 3 gig? Its cheaper than buying 64bit xp or vista I suppose.I've been watching my paging file while flying long flights and it has never exceeded 1.50 gig with a system managed paging file of up to 4 gig.I don't know though I'm just a boring flyer with nothing extra (except for addon Planes) so maybe thats why I don't see these issues; and it could be I'm completely wrong.Just my two cents worth,Good luck,Sean

So if I read you right your suggestion isIf you have 3 or 4Gig of ram and you are experiencing OOMs , then remove some RAM. Different approach I suppose :( Mark

I don't know though I'm just a boring flyer with nothing extra (except for addon Planes) so maybe thats why I don't see these issues; and it could be I'm completely wrong.

You do realize a detailed add-on scenery can add as much as 300-400Mb to the scenario? Add custom AI traffic to that, which at busy airports can account for an additional 200Mb and you'd be getting very close to tipping over, without even as much as advancing the throttles. Your mediocre system specs are paradoxically doing you a favor...just out of curiosity, is your onboard vid card PCI-E, and if so, how much RAM does it have? PCI-E cards map all their memory to the user space, thus reducing memory available to the system (or something to that effect). Ironically, the more powerful a card a user has (as in the more onboard memory), the higher the likelihood of an OOM event taking place.

Yes, I understand about the demanding resources an add-on scenery takes and also AI traffic; which coincendently I use none due to the constant issues during approach or waiting at the hold line for takeoff for 45 minutes. When your flying at 34000 feet over the pacific or atlantic scenery doesn't matter much; granted on landing or takeoff its nice to look at but my enjoyment with FS is to fly the plane, learn systems, perform different forms of approaches etc not look outside and admire buildings, birds or other aircraft. I go to my local airport to do that. Nothing against that I understand other peoples enjoyment but this is not what this topic is about.It is a PCI video card, ATI Mobility Radeon X1300 which says it can use up to 512 meg shared with the system memory. I am planning on building my own home computer which will only have 2 gig memory because I'll be running XP and FS9; my old one went to one of my daughters when I found out I could use my laptop for FS; just trying to satisfy the wife and my two teenage daughters so when I do buy one they will be alright.But what you said does make sense and thats what has been said in the commercial forums concerning these newer addons coming out. They are much more demanding than 5 years ago so if your throwing in 5-10 addon sceneries plus 100% AI your asking for issues. But lgvpilot1 said what I'm saying; try running only 2gig memory and see what happens if all other troubleshooting fails.Sean

The OOM issues have nothing to do with the amount of ram you have. It's a 32bit OS limit.And I'll quote the FS developer....Normal Win32 processes have 2G of address space, out of the 4G available. The remaining 2G is left to the OS for its needs, drivers, etc. This is completely independent of physical RAM - this is how much virtual address space each process gets.Read it here>>>http://blogs.msdn.com/ptaylor/archive/2007...ress-space.aspxAnd here>>>>http://msdn.microsoft.com/en-us/library/aa366521.aspxAnd for the record switching to 64bit cured the OOM issues I had. They are gone.

I have AES. I will disable it and try if it would make a difference.Al

Mark, I turn off most of my sceneries and AES and when I arrived in New York, same problem again OOM. I guess the only solutionis to go with 64 and reload everything?Al