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Guest Jeffhew

OOM, 3GB switch, stutters and stuff!

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I wanted to add my 2 cents to this topic of discussion but, there are a number of threads so rather than reply to one, I thought I'd start a new thread.I recently had been experiencing the OOM errors associated with some of the higher end aircraft. Specifically the PMDG 737 and the LDS 767. For the record, this is on FS9. Having tried and exhausted every trick in the book to eliminate the problem, I finally took the plunge on the 3GB switch. There are a number of great tutorials on how to apply this switch here on AVSIM as well as other FS sites. I folowed the instructions here:http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchExcept that I used "userva=2560" instead of "Userva=2900"Once Windows and FS were properly configured, I fired up the sim with the anticipation of a child at Christmas. Everthing was great at first. However, as I taxied to the active I noticed some hitching. On takeoff, everything went to crap. Less than 1 FPS is really not conducive to satisfying flight. Needless to say I was disappointed. So, how did I fix it?This is going to rub some the wrong way, and it goes against conventional wisdom. I have read a number of threads about eliminating the page file. Now, in dealing with a problem, there comes a time where the most reasoned person will try anything to solve the problem, no matter how silly it may sound. I went to my system properties and set my VM to "No Paging File". I also applied the 3GB switch to ASv6 and ASG. As a side note RC4 won't boot for me if I apply the switch in the EXE header. I fired up the sim; really loaded it up. ASv6 with 32bit clouds, PMDG 737 w/ a 32 bit livery, AISmooth, Radar Contact, FS2Crew, as well as my standard UTUSA, GEPro, BEV, FSGenesis Mesh and 100% AI (all WOAI packages and GA-Traffic). This was a trip from KPIT to KBOS (George Grimshaw' here at AVSIM). I have never been able to finish this flight, even w/o add-ons, ending with an OOM on Approach every time. Every time, that is until this one. Put simply, It was one of the best flights I've had. No stutters except for the occasional quick hitch during weather updates. My ground textures loaded quick, crisp, and clear. I normally have my frames locked at 45 but for my PMDG and LVL D I lock them at 35, and that's pretty much where it stays. My take on the the no paging fiie is that you really aren't eliminating the file. Try this, set to No Paging File, reboot, open task manager, click on the performance tab, and notice that Windows is still using a paging file. It seems to me that what we're really doing is telling windows that "Hey, I don't want you to use a paging file for MY processes". Set up like this, swap activity was reduced to almost nothing as I ran the sim. On this flight, my ram peaked at about 85% give or take. On a second flight from KBOS to KBNA (Mach1 Design Group here at AVSIM) I peaked at 90% on the ground in Nashville. And I could still sit at the gate and watch traffic come and go. This is my experience so far. I am continuing to test and should I find any negatives I'll post them but, for now, this is the best experience I've had with the high end airliners.Now for the legal stuff.This setup works for ME on MY system which is fairly high end (specs below). Your mileage may vary. You make modifications to YOUR system at YOUR own RISK!! While I believe these to be safe, I am not responsible for any damage that may result from using these or other mods which I advocate. It seems these OOM errors have been attributed, by many folks, to memory leaks on PMDG and LVL D aircraft. It's really easy to reach that conclusion when "it only happens when I fly XYZ' aircraft" I've come to the conclusion that this isn't so. PMDG has tested and retested and come to the conclusion that the issue is conflicts of scenery, bad AFCADS, empty texture folders and so on. In some cases, they've been right. What I believe is that every designer tries to make their products compatible for the greatest number of users. It is impossible, however, to assure compatibility with every single add-on ever made for FS. I think the real issue is that add-on developers try to squeeze the most performance from their products, and use as much of a systems resources as allowed, to do so. With so many add-ons running, we're just busting the 2GB process limit. No one's to blame, no one company or add-on is the culprit. The true enemy is our ever increasing desire for "As Real as it Gets". It's amazing how far FS has come since I first flew Bruce Artwick' Flight Simulator back in 1981(82?). All those "flights" between Meigs Field and O'Hare, lol.I hope this helps you all sort things out. Don't give up if it doesn't work right the first time out. I gave up on it too, but tried again when nothing else would fix the problem. I'm so glad I did.Regards,Jeff

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Just to add that I tested with different page file sizes before settling on No Paging file. I found that the larger the page file, the greater the stuttering problem.Jeff

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Thanks for this.I experienced the same problems in my system so I got rid of the 3Gb switch and have my fingers crossed when I fly and avoid long flights.I understand and agree with you that the culprit is the swap file that is used by FS9.However, I have always thought that working with no page file was very risky as it could ultimately stop XP from booting and working!!!Are you sure you still have a page file although you set XP to have none?Very strange.Thanks anyway for your findings and contributions.Ghiom

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From an expert...1) Telling XP to use "No Paging File" means just that: No paging file is used by the Operating System. Period. Full stop.2) Is this "dangerous"? No, not in the least. What it does mean though, is that your Virtual Memory size is exactly equal to your usable RAM, instead of usable RAM + Paging File size. This is incredibly inefficient from a Virtual Memory point of view, but is not in the least "dangerous".3) I certainly understand how the paging file can cause "hitches", as you say. However... it should quickly "smooth out". That is, unless you have a memory leak!! i.e. if MSFS is contunually leaking memory, it will need to allocate more memory, which will lead to more page file writing and more "hitches".I would suggest that you monitor the "VM Size" of MSFS via Task Manager (you will need to add the column, it's not there by default) during a flight, and note if that value is continually increasing. That will tell you, with absolute certainty, whether or not you have a memory leak.FYI: It is (relatively) well known that some third-party sceneries cause memory leaks!!- Bill

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No, don't remove it. You should always use a paging file - Windows won't live up to it's full potential without it (nor will any modern operating system).One optimization trick:You might consider using the "Custom size" option, with "Initial size" and "Maximum size" set to 1.5x your RAM in MB (e.g. 1.5 * 2000 = 3000 if you have 2GB of RAM). Setting them both to the same value will prevent Windows from chaging the size of your paging file (which can be expensive when the paging file grows in size).- Bill

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Yeah, I have to agree with Bill here...now. Apparently, while I enjoyed good success initially, I've had to revert to "system managed" page file. Not sure how but, it seems maybe I failed to re-boot at some point. To make a long story short after further testing I found that things can and will grind to halt at some point. The good news is that after going back to system managed, things seem to be working out well. Just make sure what ever changes you make, you protect yourself by backing up your files, just in case. Regards to all,Jeff

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"What it does mean though, is that your Virtual Memory size is exactly equal to your usable RAM, instead of usable RAM + Paging File size"Virtual Memory (VM) has nothing to do with physical memory (RAM) as has been pointed out many times. With a 32-bit operating system VM is limited to 4Gb - the maximum size that can be addressed by 32 bits.

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"Not sure how but, it seems maybe I failed to re-boot at some point"This is waht I have read somewhere... So you had to reformat? and reinstall?However, I have also read in forums that people have never had any problem in 3 yeards ++By the way, I am testing it now and FS9 is much better (no stutters, no blurries even at x2). Too bad I'll have to revert to some pagefile.sys because of this risk hanging over me!Thanks for your feedback.Ghiom

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Hi Ghiom,Sometimes when changing the paging file size in the system properties, the system will tell you that a re-boot is required, sometimes it won't. So while a setting may appear to be set properly, it isn't actually functioning as it is set. The best advice here is that when you're making changes to system settings always backup your files and settings so you can revert back if there are problems. Also, re-boot after each change and test things out so you can find and identify problems quickly. If you make several changes at once and problems arise, you'll be hard pressed to find the true issue. Most importantly, don't ever make a change to a system setting that you do not know how to reverse. Alot of advice on forums will tell you to "change this setting to this" or my favorite, "type this into the command prompt and hit enter." Don't do anything unless you know how to revert back to where you started from. To ease your fear Ghiom, No, I didn't have to reformat or reinstall anything. What I did find, I believe, is that setting "no paging file" and later going back to "system Managed" resets/rebuilds the paging file setup to work properly with the 3GB switch. I know I have seen things about resetting the page file, but I am at a loss to remember where. The only "risk" is that without the paging file set, your system will continue to use up ram until eventually, it goes into an endless (so it seems) swap, and your system will stop responding, requiring a re-boot. I also mentioned changing the AS6 and ASG EXE files to use more than 2GB address space. Now, these programs don't use any where near the max allowed per process (2GB), but I wanted to assure that it would be able to use any address assigned. Not sure if that makes any difference at all. It certainly hasn't shown any ill effects thus far. I hope that clears things up a bit for you Ghiom. Good luck.Regards,Jeff

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Thanks very much.In fact, as I said in my first mail, I flew 2 days in a row with no page file (I checked I had no pagefile.sys under C: or anywhere else). I disable the memory dumps.I noticed very very smooth flights with no texture loading issue (by the way I am not using the 3Gb patch).My best experience ever.Then I saw you mail and thought could risk to damage everything and top of all loose my XP installation and would have to redo my system again (1 week work??).So I reverted to a fixed pagefile (2048Mb).Don't know whether this is psychological or not but flying quality does not seem as good (more stutters). With the program PageFileUsageMonitor.exe, I checked what was the level od usage of my pagefile. It ranged from 60 to 300Mb... As if it was not used...Vert strange.Now, if someone can tell he has used his system with no page file (no pagefile.sys anywhere) for very long with no issue at all, I may try again to remove mine...ThanksGhiom

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Hmmm, interesting article. Bottom line though is that it's ultimately up to the user as to what works best for their needs on their system. There are advocates on both sides it seems. I wouldn't let it throw you off of trying the 3GB switch though. It's proven to be a great tweak for many folks, myself included. I read an older thread yesterday, somewhere here on AVSIM, that said, "I was reminded of a process to defragment the Pagefile by setting it to none and rebooting setting it to system allocate and reboot. A Microsoft recommended process."This is what I did and everything is running slicker than goosesh*t slidin' through a tin horn. Sorry, regional colloquialism. :-lol I also see where others have noticed the issue of having no paging file set and seeing that WinXP does in fact still allocate a page file. So, I guess the best setting is the one that works best for you. As for the 3GB switch, If you follow the instructions available, you should have no problems that you can't reverse if it doesn't work out for you. All it does is allow applications to use more than the 2GB of address space allowed per process. Thanks again for the article link.Regards,Jeff *EDIT* I wouldn't mess with forcing the OS to use only system RAM as the article discusses. I think this might be alright for some folks but, for an FS system, if you force windows to use only RAM, it will force more of FS into the paging file. This will slow the sim down, cause alot more stutters and so on. Remember that VRAM is going to be alot slower than your system RAM. I think with a system managed paging file, windows will try to keep as much of the program you are currently using in system RAM, dynamically moving the other running apps to the background. That's just my guess though.

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Pretty much agree. I spent most of last night reading a lot of threads from a google search (no pagefile) on this subject. Whats disappointing is that you find one reasonably believable article with one point of view, then you find another that has opposite point of view.You can find testimonials from guys that have not been using a pagefile for years and having no problems to guys that have issues with "certain" programs and pagefile errors.It was interesting to read the same question over and over again,"If I have a lot of ram, do I need a pagefile?" And in further reading, in those posts a lot of ram was 1.5 gb!!! This seemed to have dawned on everyone as we started seeing and affording more than 1gb on a system.With us now having 2-4gb as almost a norm, the question of a pagefile IS certainly a valid one.Underlying problem with some threads was the insistence of the sofware looking for a pagefile.sys. Some software was written to look for pagefile.sys in order to function. Hence the issues with some folks.Does FS require pagefile.sys? No definitive answer from MS on that I could see. Nothing I read.Its a complicated subject for sure.I read the same thing about setting to no pagefile and then defragging. I think I would conclude that to be reasonable thing to do. Makes sense.But most of my conclusion is based on reader posts."My system has no issues", "My system has issues". You can find testimonials on both sides.Reference the 3gb switch. Certainly not for the average user to implement. Things COULD go terribly wrong if certain steps arent taken. As you well point out.My impression is that it is covering up issues from "other" software installed on FS. Most OOM errors, which I believe it is intended to stop and where a lot of discussion on Avsim has been detailed around,, seem to come from the installation of those jets that take 16 hours to start the engines, :), along with other high memory usage add-ons. That's what I get from reading the guys spec sheets that are trying to fix the OOM error. Again, just my impression. Seems like with as much money as you guys pay for those jets, you could get the sellers to fix their issues.If you read the threads following the release of Imginesim Hong Kong airport and the memory leak issue, it was a great example of a software company fixing their own software induced problems.Seems to me that's what you have with the fancy jets.I've never seen a OOM error on my machine. If there is one thing certain in all this mess, its that NO two systems are alike. We share hardly anything in common with our setups. And the old adage that what works for one might not work for another is pretty much the golden rule here. That I believe we can agree AND count on.Good thread, made me read and learn. Muchoism appreciato!! LOL

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"Does FS require pagefile.sys? No definitive answer from MS on that I could see. Nothing I read. Its a complicated subject for sure."The advice from Mictrosoft is clear:"To delete a paging file, set both We strongly recommend that you do not disable or delete the paging file." - my emphasis.Source: http://support.microsoft.com/kb/308417/

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>"Does FS require pagefile.sys? No definitive answer from>MS on that I could see. Nothing I read. Its a complicated>subject for sure.">>The advice from Mictrosoft is clear:>>"To delete a paging file, set both We strongly recommend>that you do not disable or delete the paging file." ->my emphasis.>>Source: http://support.microsoft.com/kb/308417/>>Ah, you missed the point of my question. Not what is recommended by MS, but DOES Fs "REQUIRE" a pagefile.sys? That is different than what is recommended. So my rhetorical question still stands and I haven't seen it answered.And just to prove, on my machine anyway, that all you read isn't exactly the truth, I decided to defrag using Perfect Disc with a "no paging file" selection in the performance tab.I selected no paging file, hit the SET button, hit the apply button and restarted.Started Perfect disc, and started Task Manager. While Perfect disc was running, the "pagefile" that wasn't supposed to be there, was oscillating between 198mb and 233mb.Go figure.

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To answer your rhetorical, I would say no, Fs does not require a page file. I would also say that windows requires a page file for FS to run at it's best.Regards,Jeff

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Even if FS9 doen't need a page file many other applications do. Unless the computer is dedicated to FS( or you are prapered to keep changing the page file settings setting I suggest Microsoft's advice is sensible.Anyway, I inderstand (though can't now find a reference to it) that the the operating system uses a page file regardless. A reference on Microsoft's site suggests eliminating the page file only when an image of the operating system is being created - dimply to minimise its size.

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