Pagefile.sys

BunBun said:

Tepid said:

Virtual Address Space is not the same as Virtual Memory.
Virtual Memory uses Virtual Address Space, but they are not the same.
Disable the Pagefile, you disable Virtual Memory

And I am done debating this issue.

Virtual Memory encompasses many things including Virtual Address Space.

I think this little debate stems for the issue of a loosely defined term. When I think virtual memory I think:

"Logically-assigned memory that may or may not exist physically. Through the use of paging and the swap area, more memory can be referenced and allocated than actually exists on the system."

Disabling the pagefile changes how the OS deals with memory, slightly, however does not change how applications address memory. And only under certain circumstances will not having a pagefile ever be an issue.

That said, for the typical user in a typical setting the pagefile is left managed by the OS. I beleive I read Windows 7 now automatically sets the pagefile to just big enough for a memory dump if need be (physical RAM + ~300mb) and only makes it larger if absolutely neccessary.

You should download Process Explorer and check out your commit charge over a day.

Since the dust is settling, I will just toss this into the fray

"Contrary to popular opinion, disabling the pagefile will NOT disable virtual memory. Virtual memory is not the pagefile. It is an essential component of the Windows system and it can never be disabled. Virtual memory is not an extension to physical memory but a system that combines physical RAM and many files on the hard disk into a unit that combines the best features of both and minimizing the limitations.

WikiAnswers - How do you turn off virtual memory in windows xp

This was in XP, but I haven't seen anything that indicates that this has changed since.

Here is a set of definitions from Black Viper:

Some definitions need to be explained:

Physical RAM ~ The amount of Memory (RAM) installed on a system. Physical RAM is "way" faster than a "paging file."

Paging File ~ The file that is located on your hard drive that "acts" like Physical RAM but is way slower.

Virtual Memory ~ The name used for the sum of Physical RAM and the Paging File. In other words: Physical RAM + Paging File = Virtual Memory. You cannot "disable" Virtual Memory even if you disable the Paging File. Meaning, 2 GB RAM + 0 MB Paging File = 2 GB Virtual Memory.

http://www.blackviper.com/WinXP/supertweaks.htm

Thus, it would seem that to say that some program is designed to use virtual memory is a misleading. More accurately it should be said that it is designed to use the pagefile.

Frostmourne said:

You should download Process Explorer and check out your commit charge over a day.

And your point being???


@seeker

Exactly. Biggest problem in this thread I think is confusing on definitions of terms. I know I am guilty of that, ive had to go back and change some things because I used the wrong terminology.

seekermeister said:

Since the dust is settling, I will just toss this into the fray

"Contrary to popular opinion, disabling the pagefile will NOT disable virtual memory. Virtual memory is not the pagefile. It is an essential component of the Windows system and it can never be disabled. Virtual memory is not an extension to physical memory but a system that combines physical RAM and many files on the hard disk into a unit that combines the best features of both and minimizing the limitations.

WikiAnswers - How do you turn off virtual memory in windows xp

This was in XP, but I haven't seen anything that indicates that this has changed since.

Here is a set of definitions from Black Viper:

Some definitions need to be explained:

Physical RAM ~ The amount of Memory (RAM) installed on a system. Physical RAM is "way" faster than a "paging file."

Paging File ~ The file that is located on your hard drive that "acts" like Physical RAM but is way slower.

Virtual Memory ~ The name used for the sum of Physical RAM and the Paging File. In other words: Physical RAM + Paging File = Virtual Memory. You cannot "disable" Virtual Memory even if you disable the Paging File. Meaning, 2 GB RAM + 0 MB Paging File = 2 GB Virtual Memory.

Super Tweaks for Windows XP by Black Viper

Thus, it would seem that to say that some program is designed to use virtual memory is a misleading. More accurately it should be said that it is designed to use the pagefile.

I agree with 95% of this except the last statement. I don't believe the program knows what physical memory (pagefile or ram) is being used as this is handled by the Virtual Memory function and is transparent to the program. Here is a link to Microsoft information on Memory Management and how Virtual Address, Virtual Memory and paging is handled.
Memory Management (Windows)

Jim

Phone Man said:

I agree with 95% of this except the last statement. I don't believe the program knows what physical memory (pagefile or ram) is being used as this is handled by the Virtual Memory function and is transparent to the program. Here is a link to Microsoft information on Memory Management and how Virtual Address, Virtual Memory and paging is handled.
Memory Management (Windows)

Jim

I'm not a programmer, so I have no idea of what a program can or cannot be designed to do, but from another portion of the same Black Viper page, the author says:

Can you get rid of the paging file? Yes and no. If you have a boat load of memory (greater than 2GB) you may be able to function just fine. Some games require a certain amount of swap space to be created to even run, no matter how much RAM is available. Also, under certain conditions, my sound card goes crazy (or does not function) in some games with no paging file (oddly enough, Age of Empires 2). If you decide to test your luck with no paging file, you are on your own. :) Please do not E-Mail me with your war stories about no paging file. Every system is different and each persons requirement of how many applications are open at a time is different.. I usually do not have one "unless something requires it that I am running that day."

This seems to indicate that a page file is sometimes necessary, depending on what a person is running at the time. Some people may never run into a problem, while others will. I'm the kind that prefers to cover all bases, even if they may not apply to me.

It also seems clear that Virtual Memory is a function of the OS, completely apart from either the RAM or page file. The latter two items only occupying it.

EDIT: It appears that you include both RAM and page file within the definition of physical memory. To my knowledge, the term physical memory only applies to RAM.

The way I understand it is physical memory is actual stored memory (RAM, pagefile, whatever) and virtual memory is just what the application sees. What happens to it after that is up to the OS and VMM.

puzzled over this question for years.
finally settled on this config after heaps of research from russonavich et.al.

all conflicting as with this thread.:) hope my pics go here.(first try)

oops. the trancend is readyboost. i always leave page file with 16% free.

i'm not really ee enough to know what dtaskmanager tells me.
perhaps someone here could ??

I'm not certain what the point was in the post with the attachments, but the only thing that I might question is the placement of the pagefile...being at the end of the drive, where the access time is longest. Since the pagefile is already slow by nature, I don't see any point in adding to that trait.

seekermeister said:

I'm not certain what the point was in the post with the attachments, but the only thing that I might question is the placement of the pagefile...being at the end of the drive, where the access time is longest. Since the pagefile is already slow by nature, I don't see any point in adding to that trait.

you could have just done me a favour by pointing out i should move page to start of drive on the second hd . ?