Originally posted by: Boztech
How exactly does one quantify the performance benefit of changing pagefile size and location, anyway?
I'll probably get flamed by n0cmonkey because he is insistant that microsoft has made their opertating system "optimized", therefore it requires no changing of settings what so ever after leaving the box...:roll:
Here is the way I look at it, you have a drive, say 120GB, you install windows, change settings to how you like your interface, install system updates and install what ever system utilities you like, so then you're using about 5GB-10GB of space, this is excluding the installation of programs in excess of 100MBs....You disable the pagefile, defragment, enable the pagefile and set it to a large contiguous file of about 1536MB, which is acorrding to windows, 1.5GB. (I do since I have 1GB of ram and would rarely exceed 1.5GB of PF) Now since this is a 120GB drive, everything, including the pagefile are stored very early on in the drive, which would be on the outer part of the platters.
You install all the programs and games you want and now your drive is using up about 50GB (in my case), well your pagefile is still there, snugly knit between your files and therefore can't move, personally, I've yet to encounter an issue with the size I've got my pagefile set at. So you run the programs you normally would run and they start to use up the pagefile, well because your pagefile is stored so early on in the drive, the programs can get close to the fastest access possible by the drive.
Had you let windows' manage the drive's pagefile, the pagefile would probably at most be using about 200MB in the beginning of the drive with peices scattered all about the drive. So in the case of letting windows' manage the pagefile, you've got multiple problems to contend with;
1. Information that is larger than the fragments the pagefile has been distributed in (say in a relatively fragmented drive with 60 fragments in the PF with 50 of them that have sizes ranging in 1MB -160MB) now you've got a game that is loading textures in with a minimum of 10MB and with an average of 100MB. So now as the pagefile is filling up to the windows' default size, all those scattered peices that have been designated as the pagefile are slowing down the writing to of the pagefile because the texture files have to be split up into multiple peices which takes processing power and then the drive has to find those fragments, write to them and continue this process.
All of this could have been so much easier with a contiguous pagefile because there would be no splitting up of textures etc. and random accessing of the drive to write to the bits of pagefile
2. Now that you've got all of those files written to pagefile and the game is loaded, this process isn't going to end, as you go through the map in a game, more and more files are being loaded and unloaded into the pagefile, so now the drive's access times are becoming a very important factor because they're slowing down the access of the fragmented pagefile which needs to be written to and flushed so that more relevant things are in there, things that pertain the game albiet more.
(I know, thats what the ram is for but when you're ram limited like in BF2 in the case of 1GB, relevant files are still important)
Since the pagefile is on the same drive as the textures being loaded, now you've got to factor in the fact that the drive is being competed for between the program being loaded and the pagefile that is being filled by the program.
3. Alright, now that you've installed more programs in your computer and you may or may not have bloat ware loading up at startup, you're now starting with a larger default page file with games for example creating a new maximum since you've now got a new minimum that has been increased through time. So instead of your pagefile being in 60 fragments, it's now in about 300 fragments
(believe it or not, I've seen a drive with 1000+ fragments in the pagefile) and because of this, other programs' installations are becoming fragmented as well which can and will become a significant problem. So not only is the drive's fragmented pagefile going to slow down the running of programs, but it will slow down it's self because those fragments are now much further down on the drive's platters, therefore not being able to have the faster transfer rates of the outer platters as much.
Mini summary:
1. Because your pagefile increases with use, it becomes fragmented therefore increasing the drives' depenancy on the access times'.
2. Since your pagefile is fragmented, all programs you run that require a good amount of the pagefile, for example games, require to be split up into size corresponding with the fragments of the pagefile therefore slowing down things a bit.
3. Because your pagefile is fragmented, it essentially folds onto it's self like an obese man's flabby man tit hitting him in the face when he goes to lie down because it's requiring more overhead to deal with the pagefile and it doesn't get the faster access times/ transfer rates of the outer platter like you do with a contiguous pagefile.
4. Because your pagefile is fragmented, your files become fragmented and then it snowballs...
5. Because you can't argue that it's "hurting performance" and it could only be improving performance of the pagefile and the drive as a whole, the only feasable arguement for doing this is that it's "a waste of time".
6. I wish I could explain this better which I could very well do but because this is a post and I'm not writing a book, I'm therefore doing a poor job at it.
7. I now expect nocmonkey to reply with some one liner in attempt to irritate me because I just wrote out this lengthy post.