Most importantly, you do not want Windows to run out of memory, so make sure that the size you specify will be sufficient. Base your decision on how much RAM you have, and how demanding your applications are. A good way to get a handle on this is to monitor free physical memory, swap file size, and swap file in use. Install System Monitor from Add/Remove Programs in Control Panel. Click the Windows Setup tab and highlight the System Tools category and click Details. Put a check in System Monitor and click OK and then OK again. You will be prompted to insert your Windows CD. After you get System Monitor installed, open it by going to Start/Programs/Accessories/System Tools and go to Edit and choose Add Item. Click the Memory Manager Category and choose the items above. Use this utility for a while to monitor what Windows is doing while you run your applications.
Choosing the Drive
If you only have one hard drive, obviously there won’t be another one in the list to choose from. In general, choose the fastest drive for your swap file. If you have a second hard drive, and it is on the Second IDE controller (Secondary Master or Secondary Slave) you should choose that drive for your swap file to reside on. The reason for this is, modern Dual PCI IDE controllers on Pentium motherboards allow simultaneous access to two drives on separate IDE channels. The technical term for this is Peer Concurrency. Drives on the same IDE channel cannot be accessed simultaneously (and also, the read/write heads on a single drive can’t be in two places at once). The benefits of having your swap file on a drive on the second IDE controller should be obvious: Windows will be able to work from the C: drive AND page to and from the swap file on the other drive at the same time! If your system uses the swap file often, this will increase performance significantly.
Setting the Swap File Size
There are advantages to setting a fixed swap file size (that is, equal minimum and maximum settings). The swap file will be a static size, which means that it can occupy contiguous cluster chains and not become fragmented. Another advantage is that since it is always the same size, Windows doesn’t have to take the time or resources to resize it. This will improve access time. The disadvantage of a fixed size swap file is that it cannot grow beyond the maximum if the need arises. (Can you say “crash”?). If you want to have the best of both worlds, a swap file that doesn’t grow and remains contiguous, yet can be increased if you inadvertently bite off more than you can chew performing some memory intensive graphics editing operation or something, then choose a minimum size that is large enough that it will never need to be increased. For example, if you set a minimum of 128 Mb and a maximum of 500 Mb, you should never see the swap file size increase, but more will be available to Windows if something screwy happens. Again, System Monitor is an excellent tool to use in making this decision.