Samples libraries and SPlat project files/audio on same drive - Create a partition?

A partition actually creates a geographic discontinuity on the disk. The main delay in accessing or writing to a disk is the movement of the heads over the surface. If the heads need to seek a location on the disk, a partition often requires the disk to move further (takes longer time) to get to the new partition boundary from the partition it was accessing. So if you have to move from a partition near the outside of the disk to a new partition near the center of the disk, it may require a greater head movement than just accessing a location on the same partition. In other words, partitioning does not automatically improve disk access speed but often makes it longer. If you put the same data on a separate physical disk, then both disks can be active simultaneously. So two separate disks splitting the data improves throughput, but two partitions (logical disks) on the same disk will often actually slow access as, in your case, as the heads jump between a sample partition and a recording partition. In general, partitioning only makes sense to organize the data, if you want to improve the access speed, you need to add a physical disk. And you can usually accomplish the same data organization just by using a new folder/directory to a single partition. Short answer: separate you projects and other stuff by putting them in their own folders on the big drive. If you are concerned about your smaller sample libraries streaming at optimum speed, you could put them on the outer partition and force them to be on the part of the drive that moves the fastest, and if you want to tune your particular drive you can test your partition setup, but geeze...
http://www.pcworld.com/article/255224/how_to_partition_your_hard_drive_to_optimize_performance.html