The Intel® RAID Controller SRCS16 may experience poor I/O performance after upgrading firmware from 713H to 713K or 713N.
The Intel® RAID controller SRCS16 has a write cache feature that can enhance I/O performance. A Battery Backup Unit(BBU) is necessary to protect the data in the controller write cache. SATA hard disk drives, have a write cache too.
Hard disk write cache is a performance enhancement whereby the device reports as completing the write command (Write Sectors, Write Multiple and Write DMA) to the RAID controller as soon as the device has received all of the data into its buffer. While writing data after completed acknowledgment of a write command, a soft reset or hard reset does not affect its operation. But power off terminates the write operation immediately and UNWRITTEN DATA WILL BE LOST.
If the controller write cache is enabled without a BBU, power-off may cause a loss of data which remains in the controller cache that has not been flushed onto the disk media. This means that there is a possibility that power-off after write command completion may cause loss of data with no BBU installed.
Intel® RAID controller BBU can protect the data in RAID controller write cache, but cannot protect the data on hard disk write cache. Intel® RAID controller SRCS16 firmware 713H can get better performance while hard disk write cache is enabled, firmware 713K/713N disabled hard disk write cache to provide more stable data protection solution for the customer.
This applies to: