"OOM Error" explained in comprehensible English

[Dirk98 354]

>Paul,>>Well I did as instructed and get a bglman.dll error. It's a>Trojan installed by Cloud9 to validate purchase (I have their>EHAM scenery). It gives me a "cannot be found and will be>disabled" type error, but prevents me from opening FS9. If I>change the app enable back to 2GB it's fine... Ideas?It is a Cloud9 problem when FS9.exe aware of >2Gb. That is fixed with the latest version of their manager. You can find it on their support forum I think, otherwise do the google search.

[Guest tmilton]

Thanks for the detailed inormation Bill, I now understand the issue much better. This particular bit of information below which was part of your post is new to me though:>Incidentally, it's also important to note that the amount of>memory on a video card can actually hinder performance rather>than help...>>...that is because the video card's memory addresses are>mapped to the operating system's slice of VAS, and therefore>reduces the total number of Virtual Addresses available the>operating system...>>For example, a video card with 512MB of onboard RAM will>consume 512MB of the available operating system's slice of>VAS, so robbing too much from the OS's slice can cause a lot>of problems. As always, this is a balancing act...Can you kindly point or link to a source so I may read up on this particular point further?Again, thanks a great deal for the informative post.

[n4gix 4,961]

>Can you kindly point or link to a source so I may read up on>this particular point further?>>Again, thanks a great deal for the informative post.You are most welcome. Here are some relevant links:http://support.microsoft.com/kb/940105http://www.anandtech.com/systems/showdoc.aspx?i=3060and here:http://blogs.msdn.com/oldnewthing/archive/.../22/218527.aspxPay particular attention to the second article titled: Kernel address space consequences of the /3GB switch.

[PhilTaylor 45]

PCI-E specwww.intel.com/technology/pciexpress/devnet/docs/WhatisPCIExpress.pdfgood general background on bus technologyhttp://arstechnica.com/articles/paedia/hardware/pcie.arsgood review of 4G and Win32http://www.hardforum.com/showthread.php?t=1035670good discussion of memory mapped devices.http://channel9.msdn.com/ShowPost.aspx?PostID=42545Basically, PCI-E implements a simple load-store flat memory model using memory mapped IO to maintain compatibility with PCI devices.This is as compared to the address remapping thru an aperture that AGP uses, the GART and the AGP miniport driver if anyone remembers.The consequence of that design choice is that the entire memory of an adapter has to be memory mapped into the process address space.

[WarpD 824]

So... we're all better off with 256mb video cards apparently.I know my 8800 GT's 768mb isn't being used... not even by FSX.

[Guest tmilton]

Thanks Phil. This is valuable information that has clarified many preconceptions.

[PhilTaylor 45]

I recall in another thread a poster indicated he was seeing 490m used on the vidcard. So I certainly wouldnt go lower than 512m.Some of the add-ons that are using 2048x2048 ( 16m ) or 4096x4096 ( 64m ) textures may use that extra space since the default is 1024x1024 ( 4m ) and 16 or 64 add up fast.As always with a PC, its a balancing act.

[Dirk98 354]

>So... we're all better off with 256mb video cards>apparently.>>I know my 8800 GT's 768mb isn't being used... not even by>FSX.From my bitter experience 512Mb is better that 1Gb video. Had to downgrade, the same GT8800 based board, but less memory. I'm happy with 512Mb now, there were issues with 1Gb, like serious stutters in some situations/locations. All problems that I observed are gone now. (otherwise it was just a faulty card, who knows).

[Guest Nick_N]

Yes, it is different.. these images are old and from an old test I ran last year.. I never posted the results because I really did not want people jacking up their bufferpool settings too high and causing other problems however, with a 768MB video card and a 1920x1200 resolution, and, very high scenery settings this is the resulthttp://forums.avsim.net/user_files/187404.jpghttp://forums.avsim.net/user_files/187405.jpghttp://forums.avsim.net/user_files/187406.jpgThis shows I can use a 256000000 bufferpool setting to use the full Vmem on the 8800GTX and still fly just fine. This DOES not raise frames however it DOES smooth out the flight in very large cities with a massive amount of scenery in the image such as NYC/LA, etc or areas with a huge number of trees, as I run a 100% AG and Scenery Complexity slider. @ 1920x1200, bufferpools to 8000000 and very high scenery settings the 8800GTX is using a MAX of 514MB circling a large city and this holds true for all large cities, not just Seattle. I set bufferpools to absorb the rest of the VM and it increases to almost the card MAXSetting up a system is defined by many things, not just specs... someone on a Matrox who may be using a very high resolution would never dare raise BP 256000000 because the resolution would force the system to run out of video memory very quicklyAlso, Memstatus does not take into account a few things and will not display the total system memory used.. for that it is best to call the task manager and check the PEAKThe test I ran above was before I upgraded to 2x2GB on that system and it was running 1x2GB system memory. As I recall the task manager listed the PEAK system memory use at somewhere around 2375 even though memstatus displayed 2040I personally run a 128000000 BP setting although I don

[Guest Hedgehog]

OK, here's a real dumb or dumber question...Where do I access the BufferPool setting in order to change it and see if it makes any difference? Thanks...Steve in Kansas

[Guest Nick_N]

Add it to the config file manually{BUFFERPOOLS}Poolsize=xxxxxxxyou must replace the {} shown above with square brackets for the config.. And I do want to warn about looking at the differences in a change like that... my system is tuned perfectly and its also running very high memory speed (DDR3).. results are not based on a 'miracle' change. Its based on knowing where things get bogged down and how that setting will relieve the issues. Its not about frames and it certainly is not going to allow someone to jack up the scenery settings and get away with that. Its designed to be used in the aid of removing stutters under the right conditions and one of the last items to be tweaked after all other settings are established, correctly, for the hardware installed.

[Guest Hedgehog]

Well, just to follow up...I changed the BP setting and it did not seem to make any difference...Didn't hurt anything, but didn't screw things up either...So I took it out of the .cfg for now...Never hurts to try! (Well, usually never!)Steve

[Guest Nick_N]

As mentioned, its a setting based on how well the rest of the system is set up and where a performance issue may lie. With MSFS if one area is out of wack you can spin your wheels on settings and config edits and usually not get anywhere. Most people make the primary mistake of running settings to high and simply dont realize it. The 2nd most popular error is a system full of startup junk killing resources before the title is ever launched. The third is poor disk and file management practice. Put a bit of the three together and tweaks like bufferpools do not seem to have any effect on stutters in turns, etc. MSFS is about finding the balance in the system between resources and application requests. Once that balance is found tweaks like bufferpools typically will show results -if- a stutter issue may be present under the correct conditions.

[Dirk98 354]

>Well, just to follow up...I changed the BP setting and it did>not seem to make any difference...>SteveThis is because, ontop of all suggestions, it has also to do with your peace of mind.

[FalconAF 213]

Nick/Phil,Very educational post here. Thanks for all the insight.But I am still curious about something I discovered that I use to prevent OOM's with FSX, and WHY it works. My system specs are:XP SP2 (32-bit)4 gig memorynVidia 8800 GTX 768mbThree 19" monitors (using TripleHead2Go with screen resolution of 3840 x 1024) and a 22" monitor "on the side" at 1680 x 1050 resolution, all running off the one vid card.I run FSX on the TH2G 3-wide monitor, and numerous other apps displayed on the 22" side monitor (FS Commander, etc). I also have Active Sky X, FS Real Time, Radar Contact, AISmooth, and sometimes other apps running.I've never had any problem "loading" all this stuff at the start of an FSX session. But there was a time I would eventually get OOM's when running FSX. Then by accident one day, I found a solution that prevents them. I opened up Task Manager and began monitoring the FSX.exe file memory usage. When it reached about 1,300,000, I would get an OOM. Note I run FSX in Windowed Mode on the 3-monitor TH2G side...this is neccesary with FS Commander to work, which is on the 4th 22" monitor. But I discovered that when I MINIMIZE FSX on the primary 3-wide display, the FSX.exe file memory use would DROP to almost 30,000. Then when I MAXIMIZED it back from the taskbar, it would STAY low and slowly begin climbing back up again, with no adverse effect to FSX (texture degradation, frame rates, etc). As long as I minimized it before it reached the 1,300,000 range again, I could run FSX all day and night without any OOM's happening. I now monitor the FSX.exe file memory usage every flight, and as long as I do the occassional Minimize/Maximize (takes less than 3 seconds) I never get an OOM. I do it ESPECIALLY about 60 miles from my arrival airport, regardless of the FSX.exe file memory usage. I've never had an OOM since...even when arriving at "high detail" airports with lots of AI traffic. At worst, I may have to do it once an hour...it takes that long for the FSX.exe file memory usage to "climb" high enough to require it.I posted this a couple times in the forum in the past, but never got a reply as to WHY it works. I'm wondering if minimizing the FSX "window" is "refreshing" the memory somehow, especially the part of the memory blocks being used by the 768mb video card. Would it be "cleaning out" 1GB memory blocks, so FSX doesn't encounter them all full and do the OOM thingie?I'm just reaaly curious WHY this works. Nick or Phil...any ideas would be welcome and appreciated. I'm also curious if this might be a way for 1GB memory card users to get FSX to "behave". Note that if you are dead set against running FSX in Windowed Mode, then this won't work for you. But for me, it is a small "inconvenience" to minimize/maximize the FSX window every hour or so if it "solves" the overall OOM problem.Note a couple other people have tried it, and it seems to work for them also. The "peak" memory usage of the FSX.exe file varies somewhat from user to user before they experience the OOM (mine OOM's at about 1,300,000, but some other users get much higher numbers before they have to do the Minimize/Maximize to prevent the OOM...might depend on total number of other apps using memory?).Rick