Xcode 7.1.1 very slow and laggy I updated to the newest Xcode version 7.1.1 in the hope, that the performance will be better. But no, performance is much worse again.

When typing a word, an indexer starts immediately and CPU is on max. In general there is mostly a process running full, even I am doing nothing. There are no other apps open, but the CPU is mostly running. (mdworker, WindowServer, Xcode, SourceKitService…)

I already disabled Spotlight from indexing my source code.

Are there any hints, tutorials or the like to tune OS X and Xcode, so it will be more performant.
I am using Swift as programming language.
Disable autocomplete, that should help.
Xcode -> Preferences -> Text Editing
"Suggest completions while typing" - uncheck it.
If you feel your Xcode is still sluggish, disable the other options, too. You may want to keep "Turn on Use Escape key to show completion suggestions" on just incase you need some hints occasionally.