Don’t forget about where your captured video will reside.
I have a similar set up.
System drive is where PPro software resides.
I use the next internal drive for captured AVI’s and projects (and any items I will import, like WAV's, JPG's, TIF's,...). Just make sure you put them in different folders. (At the root of the drive, I have a folder called “PPro”. I have sub-folders under PPro called “Projects”, and another one called “Capture”. Under Projects, and Capture, I create new sub-folders for each project.
I use the next internal drive as a scratch disk. I also separate the scratch files, by project name. That way, when I’m done with a project, I can easily delete the un-needed scratch files, freeing up HD space.
The goal is to NOT put any video, projects, or scratch files on the System disk.
Don’t forget to De-frag, very often.