Elaborate Windows XP virtual memory optimization
Virtual Memory in Windows XP is a very humble, will set it automatically when Windows XP is installed, users do not have to even bother this file. But as virtual memory to supplement and extend physical memory plays an important role in stabilizing running Windows XP, if set properly, it will affect the overall performance of your computer.
What is virtual memory?
Virtual memory is for Windows XP as part of hard disk space memory usage. Even large physical memory, virtual memory is also essential. Virtual memory on the hard disk is actually a gigantic file, the file name is PageFile.Sys, the normal state is invisible. Explorer must be closed to protect the function of the system files to see the file. Virtual memory is sometimes also referred to as a "page file" is the file name come from this file.
Setting hard disk
Optimize virtual memory, why should the hard disk settings? This is because the virtual memory file (that is often said that the paging file) stored on the hard disk to improve hard disk performance can also improve memory performance to some extent.
1. Enable disk write cache
On the "My Computer" right click select "Properties -> Hardware", open the Device Manager to find the hard drive is currently in use, click the right mouse button and select Properties. In the "Policy" page attributes of the hard disk, open the "Enable write caching on the disk."
This option will activate the hard disk write cache to improve disk access speed. However, to note that, after this feature is turned on, if the computer suddenly loses power may lead to irreparable data loss. It is best to re-open this function in the presence of the UPS case. Of course, if you usually do not carry out what is important to use computer data processing, no UPS does not matter, this feature does not cause too much damage to the system
2. Open the Ultra MDA
In Device Manager, choose which IDE ATA / ATAPI controllers "Basic / Secondary IDE Controller", click the right mouse button and select "Properties" to open the "Advanced Settings" page. The important thing here is to set up the project "Transfer Mode", the general should choose "DMA (if available)."
3. Configure recovery options
When the process of saving Windows XP running encountered a fatal error memory snapshot will be a file for use when debugging the system, for most ordinary users, this file is useless, but will affect the performance of virtual memory . So it should turn it off.
On the "My Computer," right-click and select "Properties -> Advanced", "Settings" button, select "Advanced" page in the "Performance Options" in the "Performance" click below. There is a "memory usage" option, if it is set to "system cache", Windows XP will use about 4MB of physical memory as read-write disk cache, so that you can greatly improve the exchange of data between physical memory and virtual memory speed. By default, this option is turned off, if the computer's physical memory is relatively abundant, such as 256M or more, it is best to open this option. But if the physical memory shortages, or the default option should be retained.
Set the page file
Calculation of the size of the page file
For a different computer, the page file size is not the same for each. About paging file size setting, there are two widespread the "formula", "physical memory X2.5" or "physical memory X1.5". These two calculation methods is certainly convenient, but does not apply to all computers. Set the page file size is the most accurate way is to look at the size of the page file in the normal operation of the computer is actually used.
Can be monitored by Windows XP comes with logging page file size normally use a computer, to perform the most accurate settings, follow these steps.
First, in the "My Computer," right-click and select "Properties -> Advanced", click "Properties" "Settings" button below, then select "Advanced" page, click the "Virtual Memory" below " change "button. Select "custom size" and "initial size" and "maximum" are set to 300M, this is only a temporary setting. After setting, restart the computer for the settings to take effect.
Second, go to "Control Panel -> Performance and Maintenance -> Administrative Tools" and open "Performance", expand "Performance Logs and warnings," Select "counter log." Right-click in the right-hand window select "New Log Settings";
三、随便设置一个日志名称，比如“监视虚拟内存大小”；
四、在“常规”页中单击“添加计数器”按钮；
在“性能对象”中选择“Paging File”，然后选中“从列表选择记数器”下面的“%Usage Peak”，并在右侧“从列表中选择范例”中选择“_Total”。最后单击“添加”和“关闭”按钮。
五、别忘了记住“日志文件”页中的日志文件存放位置和文件名，我们后面需要查看这个日志来判断Windows XP平常到底用了多少虚拟内存，在这个例子中，日志文件被存放在D:\Perflog目录下；另外还要设置“日志文件类型”为“文本文件”，这样便于阅读。这时你可以看到刚才新建的日志条目前面的图标变成了绿色，这表明日志系统已经在监视虚拟内存了。如果图标还是红色，你应该单击鼠标右键选择“开始”来启动这个日志。
这个日志文件记录这一段时间中页面文件的使用情况，注意这里的单位是%，而不是MB。通过简单的计算，我们就可以得到页面文件的最小尺寸，公式是“页面文件尺寸X百分比”。比如这个例子中，虚拟内存最大的使用比率是31%，300MBX31%=93MB，这个值就是虚拟内存的最小值（注意，300MB是前面的设置的临时值）。
如果物理内存较大，可以考虑将页面文件的“起始大小”和“最大值”设置为相等，等于上一步中计算出来的大小。这样硬盘中不会因为页面文件过渡膨胀产生磁盘碎片，其副作用是由于“最大值”被设置的较小，万一偶然出现虚拟内存超支的情况，可能会导致系统崩溃。
设置页面文件
现在回到“虚拟内存”的设置对话框中选择自定义大小并按照上面的计算结果分别设置“初始大小”和“最大值”。这里我们将“初始大小”设置为91M，而将“最大值”设置成了200M，这样比较保险。
对页面文件进行碎片整理
Windows XP运行时需要大量访问页面文件，如果页面文件出现碎片，系统性能将会受到严重影响，而且会缩短硬盘的使用寿命。所以我们很有必要对页面文件定期进行碎片整理。
不过别忘了，页面文件是系统关键文件，Windows XP运行时无法对其进行访问。所以对它进行碎片整理并不是一件容易的事情。我们有两种方案可以选择，一是安装Windows双系统，然后启动另外一个Windows对Windows XP所在的分区进行碎片整理。二是使用专门的工具软件，比如System File Defragmenter等。