Creating smaller partitions is waste of space due to the fact that on any given partition you have limited the amount of data you can store there. What happens when a directory or application or game requires 200MB and you only have left, 100MB on one partition, 300MB on another, 200MB on another, and 50MB on another.
In reality, if you had not broken up the drive into so many smaller pieces, you would have 650MB. But because this is split up, you have tons of wasted space that cannot be used.
Separate physical drives with one partition on each would be the ideal way to go.
btw, one reason the slave drive is not showing up may be due to it being defined as an active primary partition... it may be setup with the same drive letter (in this case c🙂 as your master drive.