No, its suggested by folks much smarter then me not to place media on the same drive that your apps are on (i.e.,the system drive). Accessing the apps AND media off the same drive can slow down things dramatically.
Though for HD work I would tend to want an external drive with better access time then FW800. Of course that is dependent on the format and compression type of your media.
As and example, since I want to be able to use Red, Epic ,H.264 and AVCHD (large and/or highly compressed media files) I purchased this
https://www.dulcesystems.com/html/pro_dqg2.html
Which is a high speed/performance PCIE based system. My systems runs like butta 😀
Tom Daigon
PrP / After Effects Editor
http://www.hdshotsandcuts.com
https://www.youtube.com/watch?v=DxPrG3WUyz8
(Best viewed at 1080P and full screen)
HP Z820 Dual 2687
64GB ram
Dulce DQg2 16TB raid