- you cannot stop fragmentation however its not such a problem on a SSD.
- Make sure defrag is not scheduled in windows for the SSD
- Make sure that TRIM is enabled for the SSD. 2/3 are defaults setting for w8.1
- If running 4G RAM or less move the pagefile off the SSD to the HDD
- Move the USer folders to the HDD
All the above lengthen the life of the SSD
For a Uni laptop a reasonable size HDD is required (500g plus), an external back up drive is essential with a nightly backup routine strictly adhered to [had to rescue too many students data over the years :0(.]
For speed perhaps the best thing in this case may be a hybrid drive - SSD part for the op system and HDD part for the data.