Why did you partition it like this in the first place?
Windows XP (With ntfs) is usually fine with handling large drives and large numbers of files. Many programs are not designed to be installed on anything but the system drive.
Those who say partitioning your disk results in measurable performance gains are living in the days of Fat and Fat32. NTFS removes some of the ugly ugly hacks made to fat to make it support large disks.
The only exception is that the pagefile (what you called pseudo ram) can benefit from being on it's own partition, but the differences are small, and only show up if your system is severely hampered on ram (128MB or less). Sure, placing temp files on thier own partition can help, but configuring that is a nightmare, and you're better off not wasting your time for gains so small.
Defragmentation also usually results in negligible performance gains. Again, the FAT filesystem that Win9x uses suffered from fragmentation problems, but NTFS generally handles itself fine without defragmenting. Also, if you have large files on the volume, the windows defragmenter ignores fragments over 64MB. Some files are constantly in use by the system, and therefore are impossible to defragment.
Please see this article: http://en.wikipedia.org/wiki/Defragment#Myths