Configuring InnoDB I/O Capacity a significant benefit. For busy systems capable of higher I/O rates, you can set a higher value to help the server handle the background maintenance work associated with a high rate of row changes. Generally, you can increase the value as a function of the number of drives used for  InnoDB  I/O. For example, you can increase the value on systems that use multiple disks or SSDs. The default setting of 200 is generally sufficient for a lower-end SSD. For a higher-end, bus-attached SSD, consider a higher setting such as 1000, for example. For systems with individual 5400 RPM or 7200 RPM drives, you might lower the value to 100, which represents an estimated proportion of the I/O operations per second (IOPS) available to older-generation disk drives that can perform about 100 IOPS. Although you can specify a high value such as a million, in practice such large values have little benefit. Generally, a value higher than 20000 is not recommended unless you are certain that lower values are insufficient for your workload. Consider write workload when tuning  innodb_io_capacity . Systems with large write workloads are likely to benefit from a higher setting. A lower setting may be sufficient for systems with a small write workload. The  innodb_io_capacity  setting is not a per buffer pool instance setting. Available I/O capacity is distributed equally among buffer pool instances for flushing activities. You can set the  innodb_io_capacity  value in the MySQL option file ( my.cnf  or  my.ini ) or modify it at runtime using a  SET GLOBAL  statement, which requires privileges sufficient to set global system variables. See Section 5.1.9.1, “System Variable Privileges” . The  innodb_flush_sync  variable, which is enabled by default, causes the  innodb_io_capacity setting to be ignored during bursts of I/O activity that occur at checkpoints. To adhere to the I/O rate defined by the  innodb_io_capacity  setting, disable  innodb_flush_sync . You can set the  innodb_flush_sync  value in the MySQL option file ( my.cnf  or  my.ini ) or modify it at runtime using a  SET GLOBAL  statement, which requires privileges sufficient to set global system variables. See Section 5.1.9.1, “System Variable Privileges” . If flushing activity falls behind,  InnoDB  can flush more aggressively, at a higher rate of I/O operations per second (IOPS) than defined by the  innodb_io_capacity  variable. The  innodb_io_capacity_max variable defines a maximum number of IOPS performed by  InnoDB  background tasks in such situations. If you specify an  innodb_io_capacity  setting at startup but do not specify a value for innodb_io_capacity_max ,  innodb_io_capacity_max  defaults to twice the value of innodb_io_capacity  or 2000, whichever value is greater. When configuring  innodb_io_capacity_max , twice the  innodb_io_capacity  is often a good starting point. The default value of 2000 is intended for workloads that use an SSD or more than one regular disk drive. A setting of 2000 is likely too high for workloads that do not use SSDs or multiple disk drives, and could allow too much flushing. For a single regular disk drive, a setting between 200 and 400 is recommended. For a high-end, bus-attached SSD, consider a higher setting such as 2500. As with the innodb_io_capacity  setting, keep the setting as low as practical, but not so low that  InnoDB  cannot sufficiently extend rate of IOPS beyond the  innodb_io_capacity  setting. Consider write workload when tuning  innodb_io_capacity_max . Systems with large write workloads may benefit from a higher setting. A lower setting may be sufficient for systems with a small write workload. 3127 Ignoring I/O Capacity at Checkpoints Configuring an I/O Capacity Maximum