NDB Cluster Configuration Files Some operating systems may provide for a maximum process niceness level of 20, but this is not supported by all targeted versions; for this reason, we choose 19 as the maximum  nice  value that can be set. A  thread_prio  setting of 9 is mapped on Solaris to the special FX priority value 59, which means that the operating system also attempts to force the thread to run alone on its own CPU core. • Solaris : Setting  thread_prio  on Solaris sets the Solaris FX priority, with mappings as shown in the following table: • Windows : We map  thread_prio  to a Windows thread priority value passed to the Windows API SetThreadPriority()  function. This mapping is shown in the following table: Table 23.15 Mapping of thread_prio to Windows thread priority Table 23.14 Mapping of thread_prio to FX priority on Solaris thread_prio  value nice  value 7 -8 8 -12 9 -16 10 -20 thread_prio  value Solaris  FX  priority 0 15 1 20 2 25 3 30 4 35 5 40 6 45 7 50 8 55 9 59 10 60 thread_prio  value Windows thread priority 0 - 1 THREAD_PRIORITY_LOWEST 2 - 3 THREAD_PRIORITY_BELOW_NORMAL 4 - 5 THREAD_PRIORITY_NORMAL 6 - 7 THREAD_PRIORITY_ABOVE_NORMAL 4135