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Guest markcable

Swap file size for FS9 in XP and location

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Hi there,Recently while flying from VHHH to LFPG, using PMDG's 747-400, Radar Contact 4.3, NDAC3 and Airliner Pilot, I had a CTD with an error message saying that "Your computer has run out of memory, try freeing up some Hard Disk space".My question is this.I currently use a 100GB SATA HD partitioned into 2 x 50 GB Partitions C: & D:.C: is used for windows and applications and has about 3GB free, while D: is used for exclusively FS9 and add-ons and has about 3GB free. Does Windows XP use the C or D partitions for the swap file? as i guess this was the error that popped up.I currently have 2Gb RAM and FreeRamXP Pro tells me that I have approx 6-700MB resources free while flying.If anyone could help it wuld be most appreciated.regards, Mark.Sony Vaio AR11BIntel Core Duo T2300, 1.66Ghz2Gb SDRAM DDR2 (533Mhz)Nvidea Geforce 7400 256Mb100GB SATA HDFS9.1FSGenesis mesh for Europe, USA & CanadaUltimate Terrain For Europe, USA & CanadaVFR TerrainUK2000 AirportsAirliner PilotCargo PilotRadar COntact 4.3FSNavigator 4.7AESLarge number of compatible airports for AESAerosoft LFPG, German Airports 1-4, Imaginesim KATL etcPMDG Beech 1900C, PMDG 737 600-900, PMDG 747-400 +FLevel D767, PSS 777, Flight 1 ATR 72

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Hello Mark,Right off I noticed that your free space on BOTH hard drives is well-below the critical 10% which should be free for any partition where Windows is installed to run properly. Since your FS and WINDOWS both have very little amount of space, the swap file will be limited in size. With 2GB RAM, your swap file should be AT LEAST as large as RAM itself and located, ideally on a partition OTHER than where Windows is installed. Since you have only one HDD, then locate the swap file on the D: partition. BUT, free up space on BOTH partitions first if you can. For example, if you have the original downloaded files for add-on sceneries and installation files for aircraft, then copy them onto a DVD and erase them from the HDD. Try to have AT LEAST 5-6GB free space if possible, particularly on the Windows drive (C:). Your system will slow down if your free-space decreases to this level or continues to decrease even further.The swap file can be set by RIGHT-CLICKING MY COMPUTER - PROPERTIES- ADVANCED - PERFORMANCE - SETTINGS button - ADVANCED tab - under virtual memory section, click CHANGE and check the swap (page)file size. If it is set to system managed, you can leave it but I recommend settings FOR MINIMUM and MAXIMUM TO BE THE SAME. Microsoft does not say this, but setting min = max. eliminated pagefile fragmentation. Set the page file to RAM plus another 500MB-1000MB which should be fine - this means 2500 - 3000MB but you need free space as I mentioned above. To set it, select the custom size portion and type in the values. Make sure you also select which DRIVE (partition in your case) you want - so you would select D: drive.Hope this helps.John

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Hi John,thanks for your fast response, I have managed to free up the C: drive now to 8GB, but I can't free up any more on the D: drive. All my downloads and Installs are kept on a seperate external drive, so they don't effect the D: drive size. With 8Gb now free will I be able to use the C: drive for the swap file?regards, Markp.s. I have also defraged both drives.

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With WinXP you should not try to set the swap flie size. That was an old trick used for Win 98. Not necessary at all. Use default settings to allow windows to manage file size and set it to C drive. Reboot system. You should be good to go. The OOM problem is a FS9 and FSX shortcoming. Depending on the AC you're flying are the textures 32 bit or DXT??Bill M

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Hi Bill,Textures depend on what aircraft it is, with the leveld 767 i use DXT3, I just use the default PMDG747 liveries. I have now managed to free up 4.2GB on D:regards, Mark

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Hi Bill,I work in computer technical support and, while XP can manage the swap file size itself, it will also lead to pagefile (the NT/2000/XP term for swap file) fragmentation over time. And pagefile fragmentation is something that will DEFINITELY slow down the system. We see this in our workplace all the time. So setting the pagefile to a large but FIXED size (min same as max) is the best to avoid fragmentation of the pagefile. The pagefile fragments because Windows constantly changes its size, therefore the file occupies different sectors of the hard drive at different times as it is varied in size by Windows. With a fixed pagefile, Windows will STILL be able to "intervene" and increase the size of the file if it is too small but it will also give you a warning. In any case, when you have 2GB RAM and a pagefile of 2.5-3GB, you'll be fine, I assure you.Mark - no problem putting the pagefile on the C: drive. Since this is where you have free space, that's your best and only choice for the file.Good luck.John

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>Hi Bill,>>I work in computer technical support and, while XP can manage>the swap file size itself, it will also lead to pagefile (the>NT/2000/XP term for swap file) fragmentation over time. And>pagefile fragmentation is something that will DEFINITELY slow>down the system. We see this in our workplace all the time. >So setting the pagefile to a large but FIXED size (min same as>max) is the best to avoid fragmentation of the pagefile. The>pagefile fragments because Windows constantly changes its>size, therefore the file occupies different sectors of the>hard drive at different times as it is varied in size by>Windows. With a fixed pagefile, Windows will STILL be able to>"intervene" and increase the size of the file if it is too>small but it will also give you a warning. In any case, when>you have 2GB RAM and a pagefile of 2.5-3GB, you'll be fine, I>assure you.>>Mark - no problem putting the pagefile on the C: drive. Since>this is where you have free space, that's your best and only>choice for the file.>>Good luck.>>JohnThat's why there are defrag programs. I also work in computer support for 20 years now. That's why you should defrag before running FS9/FSX. Setting a set value for page file operations in XP will not improve performance or stop OOM faults. By default XP can handle page file optimization on it's on.Bill M

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Bill, I never said anything about defragmentation. I was talking strictly about the pagefile and nothing else. Of course, de-fragementation and cleaning up of temp files in the C:DOCUMENTS AND SETTINGS[uSERNAME]LOCAL SETTINGSTEMP folder and the C:Documents and SettingscagbabaLocal SettingsTemporary Internet FilesContent.IE5 folder as well as the C:WINDOWSTEMP folder AND along with doing regular CHKDSK /f/r (once every 1-2 months) is the single best way to keep performance high. But to PREVENT the pagefile itself from fragmenting, one can set it to a high value (1.5x to 2x RAM) with min value equalling max value. The fragementation of the pagefile does have an effect on performance but it is much less than the fragmentation and accumulation of temp files. Also, if you have not run CHKDSK for a long time, like 6 months, Windows starts having issues and slowing down.John

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To add more precision on how to set the pagefile:Set it to 0. Reboot Windows. Ignore the warnings windows gives you about no pagefile and let windows set it to the minimum it wants (of 20MB). Then defragment your drive (if it needs it). Then go back and set the pagefile size as needed.

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Hi,Just want to share with you a other advice from a expert about a fixed size page file:Oh, and you can create a fixed size page file, but that will not prevent internal fragmentation of the data (that is impossible due to how the memory manager works). You can prevent physical fragmentation, but the page file is created contigously in the first place. Plus, if you use the page file enough to where it needs to expand, you're so heavily paging that your machine would be extremely sluggish. Pick up Windows Internals. It won't say "pagefile defragmenting == useless", but it will tell you how the VMM works which will tell you why it is useless. Personnaly I find wise his expertise.Cheers.

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>Hi,>>Just want to share with you a other advice from a expert about>a fixed size page file:>>>Oh, and you can create a fixed size page file, but that will>not prevent internal fragmentation of the data (that is>impossible due to how the memory manager works). You can>prevent physical fragmentation, but the page file is created>contigously in the first place. Plus, if you use the page file>enough to where it needs to expand, you're so heavily paging>that your machine would be extremely sluggish. This is very true. Locking down 4gb's of page file a will not change the way XP allocates memory. There is as tweak you can make it the system.ini that forces XP to use on board memory first before it starts using swap files.Bill M

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When the warning " Your Virtual Memory is too low. Windows will expand your file........" appears, does Windows expand that file at that time or at the next start up ( re-boot) ?

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Interesting, I see... Thanks everyone for this enlightening piece of information. It makes sense that Windows memory allocation will not change even if the pagefile is not fragmented. Mike, I found a place where there is a registry tweak to "disable the paging executive" on this link:http://www.msfn.org/board/page-file-tweak-t960.htmlAnd another place mentioning the system.ini tweak which I believe you spoke of - is this the line for system.ini for using the RAM until it runs out and then using the pagefile? -ConservativeSwapfileUsage=1Thanks again for all your comments.John

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Thanks everyone for your help,I did what you guys said and created a custom memory allocation and defrgmented my drives and everything seems to work fine now.BTW I have a 500Gb external WD USB2.0 HD, would the performance of FS9 degrade much if I used this for my Main FS9 drive instead of my internal drive on the laptop?regards, Mark

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The internal HD is almost 3 times the transfer rate of the USB drive."USB 2.0 has a raw data rate at 480Mbps""the actual uncoded transfer-rate (of a SATA drive) is 1.2 Gbit/s, or 1,200 megabits per second (Mbit/s)."....google search...more google info regarding Sustained Transfer rate:"First, since STR is derived directly from the media transfer rate, its value also depends on what part of the disk is being read; larger outer cylinders have the highest STR, smaller inner cylinders have the lowest. Second, there's the matter of whether the access is really sequential. There is a big difference between a 10 MB file that is laid out contiguously on the disk, and one that is fragmented into a dozen pieces. Once you fragment the file, you aren't doing a consecutive data transfer any more. Each fragment of the file introduces the need for an additional positioning step to the location where the next piece starts, which slows the transfer and introduces other factors into the performance measurement."The reason you defrag is to get your HD to feed the data as fast as possible. So what do you think? Want to slow that transfer down again?Heres a nice link with some USB transfer data info:http://www.tomshardware.com/charts/externa...r-rate,696.html

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Hi, There is a big difference between a 10 MB file that is laid out contiguously on the disk, and one that is fragmented into a dozen piecesThat's of course true .. that's physics.But .....This "big difference" it's a very small fragment of time .. and will be only noticed by measuring labo apparatus.In the sim it's not measurable at all :)Think at the transfer data rate speed and the speed of the read/write head of a modern hard disk .. and you will understand .. this "big difference" is a infinite small part of time :)I had this experience just for fun (I knowed it was useless)A hard disk fragmented at 37 % (oohh it's huge fragmentation!)I made some time measurements with a 1/20 s chronometer (a mariner chrono)I make the same measurements after defragResults: no visible time difference on the chronoThe myth of better performances for the sim by a defragmentation is one hard to kill :)For my part.. the most bad thing for the sim is if a antivirus (realtime scan) or any programme who check datas is runing.There you have visible difference when the sim run.Cheers.

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To the original poster. Historically I have always had a partition for the OS and a partition for apps on a single physical (or RAID array) drive. I was advised to ditch the partition and put the OS on a physical drive (or RAID array) and FS on another physical drive. I have put the OS on a pair of sata II 80gig drives in a RAID 0 (I don`t care about fault tolerance and the read perfomance is nice) and bought one of those new WD 500Gig drives dedicated for FS. I ensured that the RAID pair and the FS drive were attached to different controllers on the mobo. With this configuration I have seen a great reduction in stutters, especially on short final where it really used to annoy me.If you have a big USB hard drive for temporary storage whilst you rebuild your rig I would recommend removing the partition, even if you end up with only one large C drive.Best of luck - I spend as much time mucking around with the pc`s as I do flying! Cheers James

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