Darknut previously reported a significant performance boost using a RAM drive http://www.gamesas.com/topic/1584994-ultimate-performance-from-modded-morrowind/?hl=%2Bram+%2Bdisk#entry24882592. For my recent system upgrade I went with an M.2 SSD (Samsung 950 EVO) drive that isn't nearly as fast as a RAM drive but is 3-4x faster than a conventional SSD. The increased SSD access speed is quite noticeable in my game play, reducing lag when new cells are loading, etc. Highly recommended.