Virtual memory is only used when you run out of RAM or the program "forces" a write to virtual memory or temp files. Having more than you need means nothing unless you are short on disk space. More important is where it is. On a new system it gets placed right after the OS but it tends to get pushed to the inner edge of the disk as time goes on because it get recreated on every boot.
To get the best performance, you'll want to keep it as close to the outer edge of the hard drive as possible and, if possible, on a second Hard Drive. So when adding a 2nd Hard drive to your non RAID system, the best thing you can do is create a small 4-8 Gig Partition (let's call it D:\) right at the beginning of the new HD. Change the virtual memory location then from C to D and set the minimum and maximum to the same size (say 2048 MB). HD's move data at about twice the rate on the outer edge as they do on the inner edge so you are now permanently insured that it is at the fastest possible location.
While you are at it, might as well reset the environment variable so that temp files are also set to utilize the D partition. Next to the swap file, these are the files most accessed by windows.Since both the swap and temp files are "temporary" files, you will gain not advantage from the file protections offered NTFS and can go with the speedier (especially with large files) FAT32 for the D Partition. This makes housekeeping easy also as it's very easy to find and delete temp files. With the min and max page file fixed, and the rest of the D partition regularly cleaned, fragmentation of the page file will never be an issue.
On a single drive or RAID system, simply place the D partition right behind a small 8 - 16 GB OS partition (C:\). Then behind ya D partition, allocate E:\ for the thing you want to go the fastest (probably Games), then F:\ for Programs, G:\for Data and maybe H:| for backups.
In this manner you will optimize your use of the hard drive such that the fastest parts of the HD are reserved for what you need to go the fastest.