Virtual Memory

[mikeshn]

Does someone can explain to me what is Virtual memory???
Thanks a lot

 

[AndyHui]

All modern 32-bit versions of Windows allow programs to see, and have available to them, the entire addressable memory range for a 32-bit x86 processor: 4GB of RAM.

Obviously this is far more than the amount of physical RAM in your system. Even so, programs are allowed up to 4GB of RAM. With that much available for use, evidently the overflow from your physical RAM has to go some where. In such a case, Windows' Virtual Memory Manager will allocate pages of RAM to disk, ie the swap file.

Since accessing information from the hard disk is much slower, the idea is to keep regularly used information in RAM, and try to use the swap file on the hard disk as little as possible.....or at least, that is what a good virtual memory manager will do. It follows then that the more RAM you have, the less data will overflow your physical RAM and need to be paged from disk.

 

[mikeshn]

Thanks for your answer ...
Does swap file is located in harddrive? Right?
Also WHy 32-bit versions of Windows ? Why 32 bit? Registers are 32 bit long? Right?

 

[AndyHui]

The swap file is located on the hard drive, ie win386.swp for Win9x and pagefile.sys for WinNT/2K/XP.

Only 32-bit processors, (386 and later) support Virtual Memory. You need 32-bit code in order to address 4GB.

 

[mikeshn]

THanks a lot
I use Win2k , I make search for pagefile.sys but it can't find the file. This file is hidden.
Thanks

 

[AndyHui]

Pagefile.sys is hidden in the root directory of the system partition (ie whichever drive you installed Win2K to).

 

[mikeshn]

I'm sorry...
Last question.. Does it possible to view hidden files in win2K. Thanks

 

[AndyHui]

Of course.

Start, Settings, Control Panel.

Folder Options, click the View Tab, then select Show Hidden Files and Folders.

To show Pagefile.sys, you will also need to uncheck Hide Protected Operating System Files.

 

[mikeshn]

Thanks man