Made a few strings frozen to reduce the number of created string objects.
Check ruby syntax when starting systemd unit
Use double quotes for all string literals
Run garbage collector every five minutes to limit memory usage
When reading fan rpm and tempurature it is not neccessary to split the read string und convert the first word to integer. String#to_i already does that.
Typo in sensor filename
Supid me. Need to start garbage collector thread before looping constantly in main thread.