Page file: what is it?

[htredneck]

Can someone explain to me in plain English (tec talk makes my eyes glaze over :? ) what the page file is? should I configure it a special way? Defrag it?, Move it, etc. etc.

Thanks

 

[JesterX]

Google it

http://en.wikipedia.org/wiki/Paging

 

[htredneck]

thanks for nothing

 

[Zoron]

What do you mean, nothing?

He provided a link to the information you requested instead of posting it here. How is that nothing?

 

[htredneck]

Sorry, I didn´t mean to be so rude. I have read all of that before and I know how to Google. The reason I started this post is that I was looking for a more simplistic explanation of all that.

Just forget it.

 

[Zoron]

Data is stored as "pages" in RAM.

When physical RAM is used up, we need a remedy for these pages to be written to the hard drive, so that physical RAM can be made available for other things. The file these pages are written to is called the page file in WindowsNT/2000/XP and the swap file in Windows 9x. Without a page file, physical RAM would quickly be used up and we would see a lot of "Out of Memory" errors.

Hope that's simple enough... as I cannot think of another way to put it.

 

[htredneck]

Thankyou very much. I appreciate it. I didn´t want to start a flame war with Jesterx.

So you know where I am comming from, I am 42 years old. My first computer was a 486sx 33mhz with 4 mg ram. Back then with windows 3.1 and then with 95 and 98 it was called the swap file. You just answered my main question. I didn´t know the name changed from swap file to page file with windows xp. (NT)

Back when I only had 4 megs of ram (now I have 2 gigs) the computer was always using the harddrive (swap file) as extended ram.

Here are a few questions:
1. Is the page file as important now when computers have much more ram and ram is cheap to add?

2. Does it need to be optimized or put in a special place on the harddrive?

3. Does winows xp do a good job of managing it or is there something I could improve on it?

Thanks again

 

[Zoron]

Disable the Pagefile

Myth - "Disabling the Pagefile improves performance."

Reality - "You gain no performance improvement by turning off the Pagefile. When certain applications start, they allocate a huge amount of memory (hundreds of megabytes typically set aside in virtual memory) even though they might not use it. If no Pagefile (i.e., virtual memory) is present, a memory-hogging application can quickly use a large chunk of RAM. Even worse, just a few such programs can bring a machine loaded with memory to a halt. Some applications (e.g., Adobe Photoshop) will display warnings on startup if no Pagefile is present." - Source

"In modern operating systems, including Windows, application programs and many system processes always reference memory using virtual memory addresses which are automatically translated to real (RAM) addresses by the hardware. Only core parts of the operating system kernel bypass this address translation and use real memory addresses directly. All processes (e.g. application executables) running under 32 bit Windows gets virtual memory addresses (a Virtual Address Space) going from 0 to 4,294,967,295 (2*32-1 = 4 GB), no matter how much RAM is actually installed on the computer. In the default Windows OS configuration, 2 GB of this virtual address space are designated for each process' private use and the other 2 GB are shared between all processes and the operating system. RAM is a limited resource, whereas virtual memory is, for most practical purposes, unlimited. There can be a large number of processes each with its own 2 GB of private virtual address space. When the memory in use by all the existing processes exceeds the amount of RAM available, the operating system will move pages (4 KB pieces) of one or more virtual address spaces to the computer's hard disk, thus freeing that RAM frame for other uses. In Windows systems, these "paged out" pages are stored in one or more files called pagefile.sys in the root of a partition. Virtual Memory is always in use, even when the memory required by all running processes does not exceed the amount of RAM installed on the system."

Now defragging the pagefile, making it static and putting it on a separate hard drive will all help improve performance... but disabling it altogether likely won't. Some programs need a pagefile and will complain when you don't have one.

 

[JesterX]

Yea, if you have 2 HDs, you can set it to the pagefile is on the other hard drive. This isnt a hack or anything, just using the System Properties Control applet.

 

[JesterX]

Yeh, and PageDefrag.
I don't use it so often now, but still a good idea to use it once every month or so.

Thats only needed when the size of the page file changes. I have Diskeeper which does Offline Defrag and the only time there was a fragment in the pagefile was the first time I ran it.

 

[JesterX]

I see. I just checked with PerfectDisk Server on my rig (PerfectDisk>Diskeeper) and during offline defrag it does indeed say my pagefile had no fragmentation.
Initially I thought keeping size static only prevents the pagefile from flying all over the disk(platter).

Dude, Diskeeper, the new one, not the old one, is way better than PerfectDisk. I was a PerfectDisk fan, until Diskeeper introduced FAAST.

 

[htredneck]

Hey all:
I am back. I spent the past few days reinstalling Windows and all my programs. What a pain in butt. Anyway, I am learning to be a little more careful with the page file 😀 I am not sure what I did but I couldn´t boot windows even with the recovery disk. Now I have the page file set at 300 mb on the OS harddrive and nothing on the storage hd. I wanted it the other way around but now I am scared to touch it.

There´s something I don´t understand. If a computer has plenty of ram (2 gigs) why would the settings make a difference. I mean if the computer doesn´t need to use the harddrive as extended ram why would the settings on the page file matter?

Could the answer be "Windows" is not perfect? I don´t know enough about these things.

 

[Zoron]

Read the explanation I quoted above. It says that while programs may never use all the memory they allocate themselves, they still allocate the memory.... sometimes much more than they actually need.