Pagefile Size Windows Vista 64-bit with 8GB RAM

Surprisingly, I just did a search on this topic and nothing came back I'm curious about Pagefile Size for a Vista x64 machine with 8GB RAM. Right now I have it set at the following:

Hard Drive 1 (Western Digital Velociraptor 300GB) - System OS - 500MB (minimum and maximum)
Hard Drive 2 (Western Digital Raptor 150GB) - System Managed (right now it is around 8GB)

Any recommendations on setting the pagefile size for the 150GB Raptor? I've done searches online and read differing suggestions. Is it better to have "System Managed" or to actually set a minimum and maximum on the 2nd Drive?

With so much RAM, why do you need a Virtual Cache? It slow! It was for system with very little RAM.

I have Vista x64 and 4GB and I'm using 512MB. Lower than that or none caused my system to crash.

Do like me, start low and increase until system is stable.

Let us know what was the best!

You hear advice both ways. Some say turn it off or turn it down to minimum size of 512 meg. Some pretty smart people at Zdnet tell me it's better to let Vista manage it because of some specific ways Vista uses the page file. They were short on specifics but sounded fairly convincing.

I don't recommend turning the page file off completely - Individual applications may still need to use it occasionally because they have their own address/space limitations, independent of the OS. So even if you have way more memory than you are using, a given app could still need to page something occasionally. If the pagefile is shut off completely and therefore inaccessable, that can cause app crashes.

It's true that with a lot of RAM, you can go a long long time and may even never need it. But just in case: 512MB won't hurt anything, and you've covered all the bases.

The only thing that I know of that has to have a pagefile operational in Vista is for memory dumps when it crashes, and who go's back and ever checks those anyway?

I quote from Wikipedia "Paging is usually implemented as a task built into the kernel of the operating system."

A pagefile is never required for an application to run, as long as there is enough free ram. The pagefile is invisible to applications, and they cannot write to it or read from it. The application doesn't know and doesn't care if a specific memory region is backed by physical ram or the pagefile.

You might have an application (like photoshop) that gives a warning, if there is no pagefile, but it is not required to run.

And maybe, just maybe there exist piss poor applications that checks if one is configured, and quits if there isn't. I've haven't seen one, but cannot conclude that they don't exist.

It can hardly help performance, but it can help if you run out of memory.

Look up... obviously Crysis does. Turning off the pagefile does NOT help performance. You can argue that it doesn't necessarily improve performance (except for when you need the memory), but I can tell you it does nothing to improve it either. It's better to have one than not to have one.

The only time a pagefile is "slower" is when Windows it either writing to or reading from it. If you run out of memory and Windows needs to page to the disk, having the pagefile turned off is likely going to crash the app demanding more memory. I'd rather have a temporary slowdown than a crash... but maybe that's just me.

After doing a little more research on MS's site regarding 64-bit... if you have enough RAM installed, you may not need a pagefile. That doesn't mean turning it off will necessarily net you any gains in performance, it just means the file likely won't be used. In that case, a small pagefile still wouldn't hurt, as some apps DO require it. Don't assume that everyone can get by with 64-bit Windows, 4GB of RAM and no pagefile.

Now when you get up 8GB or more, then I'll agree that you might not need a pagefile under most circumstances. However, when 64-bit software that can suck up all that RAM starts appearing... you just may need one again.

Sorry Zoron, Crysis does not require a page file, I play it with no page file. What I’ve done is turn off my page file and then I enable it if I get a low memory warning, if you don’t get the warning ( and you won’t with 8GB of ram) then don’t enable the page file. If you don’t have enough memory (RAM and page file) Vista will just close the program using the most memory, this feature is called Resource Exhaustion Detector and Resolution (RADAR). It will also create an error report which you can read to figure out what happened, so if you try and use too much memory, Vista won’t let you and it'll tell you that, it won’t randomly crash on you.

Programs do not go, I want my memory address to be in the last 512 mb of the 3rd memory stick in your system, just as is isn't compulsory for them to be addressed to the page file.

Mikeynavey1976: what will you be doing with this computer though, if it's just plain office, word and excel stuff and games you will likely never go above 4gb memory usage and you may as well have no page file and never get any slowdowns in Vista. If however you're using CAD, GIS, graphics processing software etc. that do require tones of memory you'll have to have a page file, and probably a large one because many applications like the ones I’ve described above edit some huge files and will require more than 4 or even 8GB ram.

You do not have to have a page file so why have it if it's got the potential to slow you down, UNLESS you use applications that require more ram than you have and then you DO need a page file.

It depends on the program. 32-bit programs are limited to a process size of 2GB... so one 32-bit program running all on it's own is never going to consume more than 2GB. Obviously, if one program is near that limit and you only have 4GB of RAM installed... then you're probably going to need a pagefile. If you have 8GB installed, then yeah, chances are you probably won't NEED a pagefile... but of course that depends on what you're running.

Of course, if you don't need the pagefile and you have one anyway, you're not going to experience slowdown in either event. If Windows doesn't need to page anything, it's not going to... so the issue of slowdown becomes moot.

Of course, this applies only to 64-bit versions of Windows when running 32-bit software. Once we start seeing 64-bit software, things just might change a bit. Processes aren't limited to 2GB... instead, they have an 8 terabyte limit. Now I can't imagine any process that would need to eat up that much RAM... but certainly 2 - 4GB wouldn't be totally out of the question. That is unless programmers really start getting sloppy with their code.

Getting back to Crysis though... OK, I didn't make myself clear. Crysis itself doesn't require a pagefile, true. However your experience shows that it is possible to run out of memory when using Crysis with 4GB of RAM. Instead of constantly switching the file on and off... it's better to just leave it on and not have to worry about it. If you had 8GB, then you likely wouldn't need a pagefile at all. So, what I meant to say is that yeah, Crysis doesn't require the pagefile, but if you're running 4GB or less then Windows is probably going to want to page to disk at some point... which, in that case, it makes much more sense to have one than not. Again though, this applies to 64-bit Vista... not 32-bit.

Hester: the 2GB limit is for any one program, in 32 bit programming a single application may not exceed 2GB memory usage, this is different to the 4GB or whatever that the whole operating system can address to. So let me say that again, a single 32 bit program is limited to 2GB memory usage in Vista/XP 32 bit, but not in 64 bit. This page probably explains better than I do.

As for the upper limit of memory you’re spot on, only thing to add is that Vista may fragment the page file if you let it handle it dynamically, but not if you set it statically yourself.

No, I did NOT say that. What I did say that if a program is consuming close to 2GB and you have 4GB installed, then you're going to run out of memory. The 32-bit process can't use more than 2GB, but Windows certainly can... and so can any other program running in the background. If one process is taking up half your RAM, then there's a good chance you'll need a pagefile to avoid out of memory errors. I in no way inferred or intended to infer that a 32-bit process could consume more that 2GB of memory.

I think I was also triggered by scotteq's comment above :"Individual applications may still need to use it occasionally because they have their own address/space limitations, independent of the OS. So even if you have way more memory than you are using, a given app could still need to page something occasionally. If the pagefile is shut off completely and therefore inaccessable, that can cause app crashes. "

I thought you were backing that statement. If there is lots of free ram, a crash won't be caused by a missing pagefile.

The pagefile is not a part of that 4GB limitation. You can have as much pagefile space as you want (almost).

hester7, you too fail to get the point

Please don't take this personally, rather read this post, have a good laugh, be thankful that you learned something today and have a beer!

You did miss the point. As I've said, you can have an 8GB pagefile with 4GB of RAM, but that makes no difference in the amount of addressable memory in 32-bit Windows. It will never address more that 4GB of total memory and that includes both RAM AND pagefile. The total amount of memory used under 32-bit Windows will NEVER exceed 4GB... RAM and pagefile combined.

nuf said

No, memory usage will never exceed 4GB, because that's all 32-bit Windows can address.

http://www.brianmadden.com/content [...] ally-mean-

Even if each process has 2GB of virtual address space, they can still only share the 2GB not taken up by the kernel. Virtual address space does not equal pagefile. If it did, you'd have to have one hell of a pagefile regardless of the amount of RAM you had or were able to address.

The point I'm trying to make is that 32-bit Windows cannot address more that 4GB of memory total... PAE does get around that physical limit, but the applications also have to support it and there are no consumer applications that do. Now, when you do have 4GB of RAM installed, some address space is of course going to be consumed by hardware. So typically, you have only 3 or 3.5GB of usuable memory left for the OS. It will use this memory + pagefile to equal 4GB total. Without PAE, it will never exceed 4GB of physical usage... because it can't. Pagefile size is irrelevant... no matter how big it is, 32-bit Windows will never make use of more that 4GB of total memory... including both pagefile and physical RAM. Remember, the pagefile is a substitute for physical RAM when there isn't enough available... but again, 32-bit Windows is limited to 4GB.

To make it a bit more clear why: the pagefile is just a file, it is not memory, so you don't need to address it as memory. When Windows feels like it, it just dumps a portion of a process' virtual address space to the file. It can do this for all processes in the system. Thus, the total amount of paged out data can be enormous.

When the data is needed again, Windows will read the data back into the process' virtual address space, so it can be addressed and executed or whatever.

In non-PAE mode, each pagefile (there can be up to sixteen) can be 4GB. Making a total of 256 GB.
In PAE mode, each pagefile can be up to 16TB. Making a total of 256 TB. Of course, noone will need that much pagefile space, but it is technically possible.

It doesn¨t explain anthing of what you say. I give up.

Just show we are clear. Lets take this one:

(You do know the difference between physical and virtual address space?)

If you have installed 4GB RAM, you cannot page anything out? If you have installed 3GB, it makes no sense to have a pagefile larger than 1GB (because 3+1 is 4, and that is the maximum windows can address)? Is that what you are saying here?

Because that is completely false. If you still argue that 32bit Vista cannot possible use for example a 16GB pagefile (like I said, multiple processes can have data paged out to it), then research the subject much more in detail, please. Until then, I don't have anything more to say.

This is truly amazing. How you are trying to lecture people, in a degrading manner, when you clearly have no idea what you are talking about. I'm out. For good this time.

Hey hester7,

Can you give link that gives example of 32 bit vista or xp accessing more than 4 gigs even as a page file (or something else)...i am a little confused as i think zoron might be right; but dont really know.

hester7, I'll start out by saying that there is a lot I don't know about paging files - you might very well be making a subtle point about the page files that I am simply missing - but I have always understood that the 4 gig limit on a 32 bit MS consumer OS is a virtual limit, not physical (though it of course limits physical also), this is because the 4 gig is what you get when you max out a 32 bit binary number, in other words 2 to the 32 power is 4 gig. In other words the physical limit is BECAUSE of the virtual limit.

The reason this limits using your physical RAM is that the OS only has 4 gig of addresses it can generate and use, that's the 32 bit ceiling, 4 gig, since there are other devices that have addressable memory on them, such as your video card for example, some of these addresses out of the 4 gig total must be reserved to address them, it's not physical ram that is being reserved or used, it's the virtual address space that is limited. The lost RAM just sits there, unused, wasted. If the OS was filling up all your physical RAM there would be no addresses left over for those devices.

You mention that the PAE kernel is loaded . . .it is well known that PAE offered a scheme that got around this 4 gig limit but it is no longer used in any MS CONSUMER OS. I realize PAE is a little more complicated than we realize but it's simply no longer possible. It was tried for a time but because of driver problems it was disabled and remains so on XP and Vista. It is still used on MS server OS. I think we all know that PAE makes going past the 4 gig limit possible but this is no longer relevant. When PAE is used a 32 bit OS can actually use way more than 4 goig of physical RAM http://msdn.microsoft.com/en-us/library/aa366778.aspx

If there is a way for a MS consumer OS (not using PAE) to have many separate page files totaling more than 4 gig (and perhaps there is a way, I don't know) it would seem that it would not be possible for the OS to use these files in any simultaneous way as there would have to be identical addresses in the separate files.

Mark Russinovich spells this out very well here: http://blogs.technet.com/markrussinovich/

Again, you may understand all of this and are making a point more subtle about it, bit if so you may need to spell it out a little more and offer some sort of documentation.

NP. I'll look into it more deeply.

I'm not here to argue this point because there is too much I don't know about it. What's confusing me is PAE - as a means of getting past the 'can't use my RAM' problem I know it is no longer used on MS consumer OS versions - but it sounds like you are agreeing with that but saying that PAE is still there affecting the virtual limit. Is this correct?