In the Forums...
Posted: May 26, 2000
Written By: Keith "Farrel" McClellan
The pagefile in Win2K isn't dynamic like the swapfile in Win9x, so it is even more important to optimize your virtual memory settings for this OS than it ever was for Win9x. With that said, there are a few guidelines you should follow when optimizing your virtual memory.
- Unlike Win9x, you can split your pagefile over several hard drives. It generally isn't recommended to split up your pagefile over separate partitions, but if you have two similar speed hard drives (you could use a 5400 and a 7200 rpm drive together, but you would want to stay away from a jump of more than about 2000 rpm), splitting your pagefile over the two drives is a great way to improve performance.
- Your pagefile should almost always be larger than your system memory. If you have less than 96 MB of ram, I recommend having at least 1.5 times your physical ram size in your pagefile, and you might even benefit from 2x. If you have between 96 and 256 MB of RAM, the Microsoft recommendation of RAM +30 MB appears to work well -- but if you are at the lower range of that spectrum and do a lot of multitasking you might benefit from a setting like 1.5x RAM. If you have 256 MB of RAM, you probably only need 256 MB of swapfile space. Unless you have your computer set to full dump in case of crash mode, any more would be a waste.
To set your pagefile, go into the advanced tab of the System applet and click on the Performance Options button. At the bottom of the dialogue box that pops up, there will be a button that says change. Click that to go into the Virtual Memory screen. From within this sub-applet you can set your virtual memory settings, and Windows even gives its own recommendation for pagefile size.
I first discussed this in my Win9x/Win2k dual booting guide, but I figure that it fits in equally well here so I am going to include it. Pagefile.sys and win386.swp, other than the file names, are virtually identical and there is no reason to not share a single swapfile between both Win2k and Win9x (you can share it with other OSes as well, but these are the most commonly dual booted OSes, so…). There are two ways of doing it – you can change Win2k to use the Win9x swapfile (pretty difficult but in some ways more convenient because you have to install Win9x first anyway), or you can change Win9x to use the Win2k pagefile.
To force Win2k to use the Win9x swapfile you will need to modify the key [HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\Memory Management]. We will be modifying the PagingFiles value.
Before you continue on with this tweak, I recommend you go back and export a copy of that key as it currently exists, because it is impossible for me to create an undo key for this operation.