Yea lookup some of the sites that popatim listed.
Also make sure you run the Samsung disk and do all the optimizations that you can. I got a Evo 120 to go from 250mbps read and write to hitting the 540 read 410 write after running the Magician software. Do everything. The Performance Optimization, OS Optimization, and Over Provisioning. one of them will make a 10GB cashe partition that will help a lot with speed as well.
Also 16GB of ram means that it probably made a 32GB or similar size Page file which is a hidden file and can be why all your space is being taken up.
Do this.
1. Right Click Computer | Choose Properties
2. Click Advanced System Settings
3. Performance Tab | Click Settings
4. Advanced Settings Tab | Virtual Memory | Click Change
Then if the check box at the top to "Automatically manage paging file size for all drives" is check uncheck it. If not continue to step 5.
5. Click on your C Drive - Then below it set it to "No Paging File" Then click Set
6. Click on your Hard Disk Drive. Click on "System managed size" then click set
7. Restart your PC.
If there is no page file on your C drive then this is not the issue and something is taking up space and will want to look though the list that was given.