I used to have a full disc problem, but then I manually deleted lots of long gone stuff that included huge non TS4 files, duplicates, downloads and videos etc, and my current situation is 311 GB free of 905 GB total. I'm still aware of performance issues if I forget being strict on what I add, so I try keeping the screenshots folder under control, and also make sure to delete zip files after installing CC etc. It's so easy to fill up space with random pieces unintentionally. A good clean up - back -up routine is needed even when having 311 GB free.