Changing cache option has a significant performance impact on Intel® RAID Controllers.
Some adjustable cache options and settings for each logical drive are available in the Intel® RAID Controller. For optimal performance with a majority of applications, Intel recommends the following cache options:
- Write Policy: Write Back
- Read Policy: Adaptive Read Ahead
- Cache Policy: Direct I/O
|Note||Some Intel® RAID Controllers do not provide embedded cache and do not have the cache options described above. On non-cache controllers, you may find the option to enabled or disabled disk cache. See the controller Hardware User Guide or Technical Product Specification for cache details specific to your controller.|
To avoid data loss, the RAID firmware changes Write Policy to Write Through whenever a backup battery unit is not present or does not have sufficient level of charge. To prevent changing this setting, you can uncheck the Write Through for failed or missing BBU option.
Operation of the Intel® RAID Controller in a production environment with the cache setting set to write back without a battery backup module installed on the Intel® RAID Controller is not recommended and may result in data loss in the event of a power interruption or other system-related issue.
For more details regarding performance measurement, cache options, and other settings affecting performance, refer to Configuring RAID for optimal performance white paper.