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744 memory usage

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Hello,Now 400 hrs with fantastic 744 without any major problems.However with new Aerosoft Mega eddf scenery, FS Meteo, RC4 and moderate AI I did suddenly get CTD (my very first with 744!) at short final after 10,5 hrs flying. Cause was out of memory. I do have relatively powerful pc with 1,5 gig memory (and pagefile disabled).I did fly same leg (SBGR-EDDF) the with pagefile enabled and no CTD but some stutters in finals. Since then I have done some testing and I do notice that with mega EDDF memory usage is very high -> up to 1.4 gigs. Also 744 requires a lot more memory than LDS 763, all PSS, NG I think. With my CTD flight reflow I did get following mem usage. At the gate SBGR mem usage was 0,9 gig with all set + RC and weather loaded. During the flight it does increase peaking at arrival stage up to 1.4 gig.Is this normal? Best Rgs Perttu

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Guest

ive found that with addon scenery, lots of ai, and a high quality VC, you need a pagefile running or else you will get CTD

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Guest lszh

HelloOn my system (2 GB RAM) it looks like a combination of PMDG 744, PMDG 744F, complex scenery and time of flight. I guess it's not a single aircraft or scenery that causes this effect. It's the combination. I noticed CTDs either on approach when the scenery will be loaded or after landing when I change to spot view.The chance to get a CTD depends on the time of flight as well. Complex sceneries involved in CTD on my system are:EDDF Mega Scenery AerosoftLFPG AerosoftEGLL Pro UK2000KPHX SimFlyersRJBB Overland.... and so onI've already tried several Windows page file settings: no page file, fix size or Windows managed. No help at all. From my point of view it looks like a memory management issue of Windows. The combination of a complex aircraft, complex scenery at destination and several hours of flying will cause this memory problem. Very annoying by the way.Has anybody tested different RAM and page file configurations so far? RAM 2 MB or 4 MB???Best regardsBrunohttp://www.precisionmanuals.com/images/forum/pmdg_pf.jpg http://www.precisionmanuals.com/images/forum/747400.jpg http://www.precisionmanuals.com/images/forum/ng_driver.jpg

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Guest detector

Microsoft "white papers" say you can get into trouble even with 2GB RAM (it still uses the page file). I had a couple of CTD`s a couple of weeks ago with my 2 GB RAM. Then I moved my page file away from the system partition, and set the initial size to 1,5x RAM which is 3072, and max size 4096. I have not had any CTD`s after that. Might be worth trying.Try google, and search for "article 555223 " and "article 308417". Some interesting MS info there.

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Guest lszh

Hi AndrevThank you very much for your reply. Are you using a second physical hard disk or just another partition on the first disk for the page file?I'll give this approach definitely a try. :-rotorBest regardsBruno

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Guest detector

Hi Bruno,I have only one harddisk, partitioned in 3. C: for WinXP and windows related programs, D: for FS only, and E: for tons of other stuff plus games. I setup my page file on the E: partition.

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hi alex,would you be so kind to explain page file? how would one get/make/do one?thanks,max


Tom James

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Guest Phill

A friend of mine wrote this article ,might be worth a read.Phill-----------------------Virtual Memory A bit of history first.Back in the days of the first microcomputers like Apple and Commodore with ram sizes like 4k and 8k and later with 48k and eventually 64k machines, programs were written to operate within those set amounts of ram. Instead of disc access for reading and writing, the early machines used cassette tape. Programs were written and saved on cassette and to load them you would type LOAD PROGRAMNAME then type RUN. Simple and effective. When floppy disk drives came into use, things became a little more automated and programs would load up with a simple command and run.To get more performance from these machines, a good quantity of ram was the way to go as you could load more than one program into electronic ram and switch between them. I had an Apple ][e with 384k of ram, a rocket chip (4x faster) and a 20 mb scsi hard drive and running Apple

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Guest Clansman

Hi everyone,guys, let's not divert from the first post. The issue is unarguably a full-memory situation. Virtual memory, to be more precise.The pagefile is not evil. There's a reason for it's existence, and a good one, I might add. The memory seen by the operating system is called Virtual Memory (VM for short), which is the linear sum of the physical memory plus the pagefile.If Perttu has no pagefile, then his VM is just the physical RAM installed. When the VM gets full, there's not much the operating system can do:- hangs because it can't fullfill new memory allocation requests so it crosses his arms and plays dumb;- kills applications (in a best-effort way to find the application that leaves the smallest impact trace when it's killed) to free up memory to others;- all of the above.Windows killed Flight Simulator - hence the crash to desktop - probably because it was the biggest memory hog in the system (windows' algorithms for selecting the applications to kill are proprietary, but a memory hog application is probably broken or leaking so...). Eventually this could be seen in the event log...If he had a pagefile, it would be used causing the machine to become a bit slower if only a few sporadic MB were needed and a lot slower if a couple of hundred MB were requested in successive requests.Your description shows a lot of scenery addons and of course it reflects as a much bigger memory footpring, at least when closing to such addon airports. Added to that factor, the PMDG model is very complex as we all know, soooo 1+1=LOTS OF MEMORY CONSUMED!Bottom line is: It's not at all a good policy to have no pagefile. If the machine thrashes (gets very very slow) frequently due to pagefile use, then more RAM is needed to alleviate pressure on the pagefile. The pagefile is there for a good reason: to provide extra memory for the operating system, but it's meant to be used only sporadically (for most computing environments). Consider for example a 3d designer: maybe all he needs for working are 1GB of memory. However when rendering a big project he may need 4GB and the pagefile fits perfectly for this situation, avoiding the costs of having 3 expensive empty extra GB.Hope I cleared some ideas here.Cheers everyone,Pedro Venda.

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Guest detector

Hi Bruno,One step forward anyway! I cannot remember if moving the page file to a separate HDD is better than moving it to antoher partition or not. Others can maybe give an input here. But the next step would be to try the 1.5x your RAM rule for MIN size, and the MAX size say 2x or more. If that does not fix it, simply set your page file to "Windows Managed". And with the experience I have with page files, I would recommend reading Pedros recent post below in this thread. I find it interesting.PS: Good luck to you all :+

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Guest lszh

Hi folksRegarding page file location: MS recommends (white paper) to place a large page file on another disk and/or partition than the Windows installation and a small page file on the Windows partition.I totally agree that the usage of the virtual memory will slow down your system. If the system is running out of memory (RAM and virtual memory) then Windows has to terminate an application. No problem if it is the FS9 at all!My problem is that Windows terminates my FS9 process with the message

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Guest cynigel

Hi Bruno,I must admit this memory issue with the 744 is a pain, and I do say "with the 744" loosely only because I never have the same problem with any other A/C.As a rule I don't get time for long duration flights (work etc.) but is was Easter out here this W/E & the other half was working throughout so I have had time to play. Since installing the 744 I have had the odd out of memory error but I put it down to my old system being a bit out of date, so I built a nice new one solely for FS & Vid editing.Specs:- Mobo - Intel 955 (not the fastest thing on the planet but stable)CPU - Intel PIV 3.6Ghz 2MB L2Memory - 4GB 667 DDR2GFX - Asus 7800GT 256MBHDD's - Primary - 120GB SATA2 Storage - 2x200GB SATA & 1 300GB SATA for backing up.FS settings: - All the sliders at MAXFPS locked to 25On the face of it the system is more than capable of dealing with FS, but much to my horror "Error - out of memory" right on the 4 hour mark of my first flight with the 744F - New system same error.. OK so I tried the 744 - Same error at or around the 5 hour mark, the "F" seems to be worse than the PAX 744.I exported the route for the LDS767 and completed the route without an issue.. I did however monitor the memory usage for the flights and the results almost shout memory leak..744F - Cold & dark on the apron - 3.7GB free RAMRunning ready for taxi - 3.2GB free RAMAt the cruise - 2.5GB free RAMNow it stayed at the 2.5GB mark for the best part of 3 hours and then in the last 2 hours of the flight started eating up the RAM at an alarming rate not to mention a 3.7GB swap. FS crashed out.744 - The figures for the 744 where about the same as for the "F" minus 1/2 a Gig and the build up at the end of the flight was much slower but the end result was the same - FS Crashed out.LDS767 - (Sorry for comparing the competition PMDG)Cold and dark - 3.7GB free RAMRunning ready for taxi - 3.5GB free RAMAt the cruise - 3.0GB free RAM4 hours 40 minutes later landing at EGKK with my OSS scenery (about the densest I have) and there is still 1.2GB free RAM.There is a stark difference between the A/C but definitely the 744's love their RAM. I'm definitely not ruling out this just being XP not able to manage the memory efficiently.Since the above flights I have had some tinkering and was very surprised to find that with more than 1.5GB of system RAM the 744's constantly gave memory errors where others did not. BUT and it is a big BUT, if I keep the system memory down to 1.5GB and give XP a 10GB swap on any drive other than the primary drive I can get past the 5 hour flight mark without running out of memory.Now although the flights are completing with the 744's we are talking ONLY JUST. My last test completed after 7 hours and we landed with 125MB of free RAM, but we landed..!I don't for one minute profess to be an expert on these things, but it looks like we have a combination of XP not coping with too much memory, FS not clearing down memory once it has no further use for it & the 744's just being a very complex memory hungry A/C. I for one would love to solve this puzzle, FS is my relaxation and I love the 744's, but almost don't want to get them out when I keep failing to complete a flight.Now before someone sets my tail ablaze, this is not an attack on PMDG or their excellent work. I own all of their A/C and have hundreds of hours clocked up in the 73's over the years (which incidentally don't suffer the memory issue) and I wouldn't hesitate to purchase PMDG's next offering without a thought, but it would be nice if they could maybe lighten the memory load a little.I can see from the lack of posts that this is not a major bug with the 744, but if anyone else has had and solved the problem PLEASE let me know how.

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