- Do you mean PS CS6 is occupying 30 GB of space while saving a particular document?
- Does this happen with only that document or with other files as well?
- Did you set that partition as Scratch disk?
- What is the file size of that file and what does it contain?
Lets optimize PS for best performance and check. http://helpx.adobe.com/photoshop/kb/gpu-opengl-support-photoshop-cs4.html
~ Arpit