What's the largest swap size you've ever set and/or used?

On my Linux machine, I've set it for 32 GB, and I've used 17 GB of it before.

On my Windows - set: 4 GB, used 3.9 GB.

you mean for the computer to use as memory?

Quote: Originally Posted by ex421 you mean for the computer to use as memory?

yea.

a.k.a page file, virtual memory, etc.

Is there really an optimum? Does Windows run faster with or without it? (Presuming that I only have 2 GB of RAM).

I know that with my quad (16 GB RAM), it doesn't need to swap unless it really has to. Once it starts though, specially for the stuff that I do, it can pretty much go on indefinitely.

Curious to find out what other people's experiences with swap files are (and varying sizes) and based on what you do/doing/have done - what are some of the largest swap file sizes that you've seen.

In my main Linux rig I used to have an entire 40gig ide hdd mounted as swap, just because. Now I just go with a gig of swap. I have the space and I never seem to need all of it. I don't know about my windows install, whatever it defaulted to. I only boot into that when I want to play Oblivion or BF:2142.

Quote: Originally Posted by alpha754293 yea. a.k.a page file, virtual memory, etc. Is there really an optimum? Does Windows run faster with or without it? (Presuming that I only have 2 GB of RAM). I know that with my quad (16 GB RAM), it doesn't need to swap unless it really has to. Once it starts though, specially for the stuff that I do, it can pretty much go on indefinitely. Curious to find out what other people's experiences with swap files are (and varying sizes) and based on what you do/doing/have done - what are some of the largest swap file sizes that you've seen.

Does Windows run faster with or without it? Try setting it to no swap file, rebooting, and waiting.

Quote: Originally Posted by joecoin Does Windows run faster with or without it? Try setting it to no swap file, rebooting, and waiting.

Waiting for what?

Ther eare some that believe with systems using over 1GB of ram, that you should disable swap files.

It will force all data through the sytem ram, wich is of course faster than the HD.

Current thinking is that is should NOT be disabled, however...it does not have to be that large...of course, I am talking about regular desktops here, and not "Heavy Metal" server apps!

It is also best to set the swap file to another hard drive that is not your main drive, or at least partion your HD, and set the swap file to the secondary partion (The one without the OS)

It is also been said that you should set the min and max to the same size to prevent "Thrashing" of the HD.


I personally set mine to 1024 min and 1024max and put it on a second HD or the secondary partition.

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Quote: Originally Posted by $SOLID$ Necro Ther eare some that believe with systems using over 1GB of ram, that you should disable swap files. It will force all data through the sytem ram, wich is of course faster than the HD. Current thinking is that is should NOT be disabled, however...it does not have to be that large...of course, I am talking about regular desktops here, and not "Heavy Metal" server apps! It is also best to set the swap file to another hard drive that is not your main drive, or at least partion your HD, and set the swap file to the secondary partion (The one without the OS) It is also been said that you should set the min and max to the same size to prevent "Thrashing" of the HD. I personally set mine to 1024 min and 1024max and put it on a second HD or the secondary partition.

Neither of my configurations really lend itself to moving it on another drive, BUT; that is something that I have done in the past, especially if I know that I am going to be dealing with large data sets.

The reason why I am asking is because when I am working on processing the results from my CFD work; in doing a compare-and-contrast type of scenario, I'm actually right at the limit of where I have set my swap size to be, usually with no more than a few hundred kB of RAM free/available. (I think the lowest I've hit is about 300-400 kB RAM free).

Having said that; aside from getting more memory (still running Windows 32bit though); is there an ideal/optimum whether it'd be in general, in practice, for both "normal desktop" size apps and for some of my "heavy duty" stuff?


In order for me to get to around 16 GB of RAM used, with a 17 GB swap file (on the quad); it is create a mesh for my CFD that's > 121 M elements on one system.

Which means, one of two things: either that I should let it run (at that point, the IOps<-> hard drive becomes the bottleneck and CPU utilization and mem IOps drop dramatically) or start looking/setting money aside to move from 16 GB of RAM to 64 GB in hopes that that should keep it "happy" for the time being.

Has anybody here (or elsewhere) ever done an extensive study on how much the swap helps (or hinders) system performance?

- * - * - * -

My current import limit for my CFD is about 8 M elements, although I have done one case up to around 18 M I think. (Different way of meshing.)

Looking at the results in two of those cases simultaneously keep my systems fairly occupied. (setting all kinds of records).

I know that historically, while for the majority of the time, a Linux system has a lot of performance benefits due to the nature of the system - once it starts swapping; it slows down dramatically. Course, I've never had a 17 GB swap in Windows (ha ha ha....I don't think Windows would be too happen about that).

P.S. my current "formula" for setting the swap size is double the amount of RAM it has. And that applies to all systems (including Linux/Solaris).

Quote: Originally Posted by alpha754293 Waiting for what?

Waiting for a long time.


Virtual memory - Wikipedia, the free encyclopedia

Quote: Originally Posted by joecoin Waiting for a long time. Virtual memory - Wikipedia, the free encyclopedia

According to the link you sent, I've already set my swap on my workstation to be the max that it can be for that version of the OS @ 4 GB.

Meaning that unless I move over to the 64-bit version of Windows XP Pro, that I might not really see much in terms of performance gain/benefit with or without swap.

Problem is, my application isn't fully qualified to run in Windows 64-bit yet (not as far as I know) nor are the drivers for the system/chipset/motherboard/video card (though I DO know that one exists for Windows XP 64 for my Realizm.

Looks like I might have to resort back to Linux to do some of the stuff. hmm...... interesting.

(P.S. If anyone's interested in testing it concurrently with me, hit me up in a PM. I don't have a lot of the games nor do I really know how to play them to assess performance levels.)

Already post a link about it , that explain it all (i guess must people do not read my threads?)

http://forums.pcapex.com/general_os_...swap_file.html

Quote: Originally Posted by goodman123 Already post a link about it , that explain it all (i guess must people do not read my threads?) http://forums.pcapex.com/general_os_...swap_file.html

The problem in my case is that as I can tell from the Linux system, it is VERY possible for me to dedicate an entire 18 GB or 36 GB SCSI drive just for the swap because of the amount of data that I work with.

I think that the largest single continous file that I have ranges anywhere between 2.2 GB and 8 GB.

So while that page works (presumably) if you have a swap file <= 2 GB; little is known (or so it seems) about it's behavior and/or performance once you start getting into 2-8 GB terroritory.

In fact, Necro and I were talking last night, and he had mentioned about the i-RAM board; and I told him that while that would be particularly useful for PCMark04 (the originally point of the discussion), I pointed out that that to me would be far more beneficial to use as swap instead.

What WOULD be interesting is if I used two (or more) of those, and tied that into the onboard SATA RAID and used that as swap. I think then I would be able to "truly" see my system shine.

Course, I'd have to get 8x 1GB PC3200 in order to make the best out of it (which is going to be quite expensive).