FS PERFORMANCE AND VIRTUAL MEMORY MANAGEMENT

[shermank 166]

A friend whose expertise is IT has an interesting thought about virtual memory management and the windows swap file. he tells me that rather than let windows manage VM, it is best to select a swap file that is only slightly larger than your ram. In other words, in my case I have 512 megs of ram, so he says my VM should be set to 513 maximum. btw, while futzing with my VM swap page size, I tried an experiment with absolutely 0 sized swap page. While this is a subjective observation, it appears that for the few minutes in which I had booted FS2002, there was hardly any difference in performance, though if I had to pick a bias, it would be smoother movement than with a fixed W98SE swap file selection.My friend reasons that 512 megs should be more than enough to handle most applications and the idea is to minimize any disk access for VM. So, I am interested in some thoughts on this theory from those of you more conversant with the techie aspects of memory managmetn by Windows.Sherm

[Guest jason2112]

I see no cause for this "a little more than your physical memory" rule. Using a swap file size of 0 of course avoids any unwanted disc activity, but can also cause problems when you do run out of memory. For example sometimes I run FS along with several addons, some graphics software and a browser. Even with 512 MB physical RAM this would not be possible without virtual memory.It has often been said that 512 MB RAM is the optimum for FS2002. Less brings you stutters, more brings you nothing. At least for the "modern" windows versions - 2000 & XP - there should be no need to tweak any virtual memory settings. I can't comment on the Win95 line, because I have never used it.Just my 2c (EUR),VOlker :]

[John_Cillis 2,406]

A large number of my "housecalls" to our remote staff with laptops have been to handle issues where people have read about these tweaks, and applied them--and saw performance suffer. I'll outline the circumstances where I would apply them, and those where I won't:Fixed swap file:-You have 256 megs of memory or less (I used to stop at 128, but apps eat more RAM these days)-And you have 95, 98SE, or MEIn this case, I would make sure installed RAM+Swap file equals at least 512Megs. A formula of 1.5 times memory came out of days of old, but I believe in fixing combined RAM (fixed and virtual) at a level of about 1.5 times your max memory "load" when you're running an APP like FS2002. That takes some research, but it avoids people having monster swap files, or swap files which are too small.Windows managed Swap file:-You have more than 256Megs of RAM,-Or you have Windows 2000 or XP.... (In which case, you'd better have more than 256 megs of RAM :) )Really, this topic is better opened in the HW forum. You'll find several people, with equal qualifications, will have different ideas, formulas, warnings, etc....The whole point of fixing the swap file is lost though if people don't combine the process with a defrag. Although I only have 256 megs of RAM, and 98SE, I let Windows manage my swap file. I don't have enough FS Add-ons to load my system down, so my swap file usage is usually 'nil.... I had it fixed, and saw no performance benefit since it wasn't being used.-John

[shermank 166]

Thanks for the advicce, Volker, and as those of us on this side of the pond have come to learn, 2 cents Euro is worth more than 2 cents U.S.$...:-)interesting, all the opinions I have heard from people outside of this forum as well as what is coming in here and over at flightsim, where I posed the same question...Sherm

[Vulcan 14]

The reasons I have heard, from various sources, for having a fixed swap file in Win9xIt stops windows growing the swap file to a very large size.It reduces the CPU load because windows uses CPU cycles to continually monitor and adjust the swap file size if it is not fixed.Now Win2000 & XP are supposed to use RAM better than Win9x so the pundits say there is no need to fix the swap file size. However if these later OS's still use the CPu to manage the swap file size then surely it is a good idea to fix the size?Incidentally, if you have a later OS then you can use Task manager to how much RAM an application, such as FS, is using and so can determine if you need a large swap file.If you run Win9x you can get the same information via TaskInfo out there on the Web.IIRC the last time I looked at FS under Win2k it was using around 250MB RAM but each time I have upgraded my CPU/mobo FS still shows around 99% CPU utilization!

[Guest jason2112]

1. FS always shows 99-100% CPU usage. Even on a Cray ;)2. I'm quite sure you will not even gain 0.1% FPS by fixing the swap file size using XP. There's no process that checks for the size of the swap file every second. I don't know the exact details (should ask my boss/professor, he knows), but only if the allocation tables of the virtual memory manager show an impeding shortage of space in this file will there be any action to increase the size. Those allocation table and statistics updates have to be made anyway, so I'm quite sure it does not hurt to leave the management of the paging file to XP.VOlker :]

[someone 0]

I've always run with 2x the ram for swap file. Especially now days if you've got less than 512MB. In one case when I had 256MB on my old computer I actually had to bump up the swap file to 1GB to get a certain program to work.FS2002 doesn't use a whole lot of memory. I ran a test a while back, and IRC FS never ate up more than 170MB of memory.

[John_Cillis 2,406]

You're one of the few people to confirm my observations about FS's memory usage.... I never measured FS2000, but FS2002 will normally take 150-170megs of ram. Their are some exceptions--Dreamfleet's Cardinal panel, and Eaglesoft's great Beechjet/Premier bundle, use up about 30 and 60 megs, respectively.I'd love to know what proggie took up 1Gig of RAM. I may have to adjust what I tell those intent on fixing their swap files...-John

[someone 0]

It was IL-2 Forgotten Battles. The sim ran fine, but I everytime I tried to enter the campaign I got out of mem errors. After increasing the swap to 1GB I was able to play the campaign.