InnoDB System Variables is 80% of a single CPU core. On a system with a multi-core processor, a value of 150 represents 100% usage of one CPU core plus 50% usage of a second CPU core. For related information, see Section 8.5.4, “Optimizing InnoDB Redo Logging” . • innodb_log_spin_cpu_pct_hwm • innodb_log_wait_for_flush_spin_hwm Defines the maximum average log flush time beyond which user threads no longer spin while waiting for flushed redo. The default value is 400 microseconds. For related information, see Section 8.5.4, “Optimizing InnoDB Redo Logging” . 3261 Command-Line Format --innodb-log-wait-for-flush-spin- hwm=# System Variable innodb_log_wait_for_flush_spin_hwm Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 400 Minimum Value 0 Maximum Value (64-bit platforms) 2**64-1 Maximum Value (32-bit platforms) 2**32-1 Command-Line Format --innodb-log-spin-cpu-pct-hwm=# System Variable innodb_log_spin_cpu_pct_hwm Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 50 Minimum Value 0 Maximum Value 100 Defines the maximum amount of CPU usage above which user threads no longer spin while waiting for flushed redo. The value is expressed as a percentage of the combined total processing power of all CPU cores. The default value is 50%. For example, 100% usage of two CPU cores is 50% of the combined CPU processing power on a server with four CPU cores. The  innodb_log_spin_cpu_pct_hwm  variable respects processor affinity. For example, if a server has 48 cores but the  mysqld  process is pinned to only four CPU cores, the other 44 CPU cores are ignored. For related information, see Section 8.5.4, “Optimizing InnoDB Redo Logging” .