nice

nice
The nice utility can be used on Linux to launch a program with a different priority level.The PR value is the process’s kernel priority. The higher the number, the lower the priority of the process. The lower the number, the higher the priority of the process. The NI value is the nice value of the process. The nice value is factored into the kernel calculations that determine the priority of the process. The nice value for any Linux process can range between –20 and +19. The lower the nice value, the higher the priority of the process.

>nice -n nice_level command

>nice -n -15 command