nice runs
utility at an altered scheduling priority. If an
increment is given, it is used; otherwise an increment of 10 is assumed. The super-user can run utilities with priorities higher than normal by using a negative
increment. The priority can be adjusted over a range of -20 (the highest) to 20 (the lowest). A priority of 19 or 20 will prevent a process from taking any cycles from others at nice 0 or better.
Available options:
-n increment
A positive or negative decimal integer used to modify the system scheduling priority of utility.