Copyright Michael Karbo, Denmark, Europe.


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    Chapter 8. The page file

    One of the most important things for the performance of a computer is its RAM its memory. A computer is normally equipped with 512 MB or 1 GB RAM, which is quite good enough. The more, the better. But Windows has its own way of ensuring that you never run out of RAM. Letting a file on the hard disk work as an extra virtual RAM does this. This special file is called a page file. Optimizing the page file can improve a computer's performance somewhat.

    The size of the page file

    A page file is then a kind of artificial (virtual) RAM. It functions as a storage extension directly in connection with the real RAM.

    From Windows' view the computer in the example above has altogether a working storage of 1280 MB. As standard, you see, Windows creates a page file of up to 150 % the size of the physical amount of RAM.

    As standard the page file doesn't have a fixed size, Windows sets some limits within which the size of the file can vary. When a computer starts up, the page file is maybe 384 MB big, but it can gradually grow in size as necessary. 768 MB is the absolute limit for the size of the file.

    This system works fine but many super users try to optimize it. This can be done in the following ways:

  • The page file is given a fixed size.

  • The page file's size is reduced to a minimum.

  • The page file is placed on a fast hard disk not necessarily the C-drive.

  • The page file is defragmented.

    Not all these points can be fulfilled; a fragmenting is especially difficult to avoid. But we can try.

    With a fixed size

    I am completely convinced that it is a good idea to give a page file a fixed size. In this way it will stay permanent on the hard disk, which is the best thing. The problem is to choose the right size. The smaller it is, the more effective it will be.

    In my work computer, I have 2 GB RAM at the moment, which is quite enough for all the tasks, I can give to Windows. So a page file isn't really necessary, and this is why it seems completely grotesque when Windows XP sets aside up to 3 GB room for a page file, as shown in Figure 47.

    Figure 47. Standard settings for the page file in a computer with 2 GB RAM installed is 3 GB (3069 MB), which is much too big.

    Find the right size

    It looks as if you can't avoid page files; for one reason or another it is recommended that you should always use a page file. The secret is to find the right size. Try starting with a fixed size of 512 MB.

    This is done from the tab Advanced in the dialog box Properties for system (see page 30) with the topmost button Settings (by Performance). On the tab Advanced click on the button Switch:

    Mark the drive the page file is to be on. It is a good idea to choose a partition, which is NTFS formatted. The very best would be if the drive were newly defragmented.

    Type in the number 512 (the size of the page file in MB) in the two fields with User defined size and click on the button Define:

    Then click three times on OK, to close the dialog box. Maybe the computer has to be restarted, and after that the new page file can be used.

    Check how much the page file uses

    If you try to trim the size of the page file, it is a good idea to keep an eye on how much Windows really uses. You do this with a console, which is called Performance.

    Open the Control panel and find the category Administration. Click on the shortcut Performance:

    A different sort of window opens up, which is divided into three window panes. This is a console, which shows the performance for lots of the processes in a computer and in Windows. We need a counter, to keep an eye on how the page file behaves.

    Click on the plus button at the top of the left window pane:

    The console works with a number of different performance objects, as they are called. They could just as well be called processes. Select the performance objects Page file in the list, which is shown below:

    Several counters can be connected to the individual performance objects. Select All counters this time. Mark the page file.sys in the list on the right. Then click on the button Add and then on Close:

    And so the monitoring of the page file starts. It is displayed as a standard with some unpredictable curves. The values are easy to follow if they are shown in the form of text. So click on the button Show report:

    In the report the maximum use of the page file can be read as a percentage (see Figure 48). In practice, you should let the console work for some days while you are using your computer. Then you will be able to see how big a page file is really necessary.

    The page file is really too big if the degree of utilization is under 10%. You can try reducing the size by half and then measure its use once again.

    The console can be stored as an MSC file so that it can be used again. If you remember to save it before shutting the computer down, the data will be saved until the next time.

    Figure 48. The console shows here that only 14% of the 256 MB page file has been used. The console can be used to monitor lots of other processes, if you are interested in your computer's output.

    There are lots of articles on the net, which describe methods of optimizing a page file. Some of them claim that it can be a good idea to place it on a completely separate drive. Others write that it is very important to keep the size down and that the file is not fragmented. It's up to you to decide how important you think these things are.


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