Xcode 6.1.1 writes to much data to disk

Recently I noticed that Xcode writes too much data to the disc. Within just 40 hours it wrote more than 13GB to the disk. See some more info about this on this screenshot. I restarted Xcode to see what actions cause this insane data transfer. I noticed that typing just one character makes Xcode write 40-50 MB of data onto the disk. As I have an SSD this makes me very "uncomfortable" using Xcode.

How can I find out where the data is written and why it is written?

Thanks for the answers in advance!