To use SRT on the Z68, the controller mode in BIOS must be set to RAID. The latest Intel Rapid Storage Technology drivers (10.5) are also required, otherwise the Accelerate tab will not be present.

 Intel Z68: The Best of Both Worlds

Two acceleration modes are supported: 

In Enhanced mode, the SSD is used as a write-through cache. Data is written to both the SSD and HDD simultaneously. If the SSD fails or either device is removed, no data will be lost. The performance increase in this mode will be less.

In Maximized mode, the SSD is treated as a write-back cache. Data is written to the SSD first and then to the HDD at intervals. If either device fails or is removed, data is likely to be corrupted. This mode offers better performance.

The acceleration mode can be changed on the fly.

 Intel Z68: The Best of Both Worlds

All existing partitions on the SSD must be deleted before it can be used as a cache. If your SSD is larger than 20GB, you can also choose to use up to 64GB as cache space. Any remainder is accessible as a standard volume.

 Intel Z68: The Best of Both Worlds

If the SSD is removed or fails, the HDD must be reset before it can be accessed again. In enhanced mode, this will not result in any data loss. If the accelerated HDD is unplugged, the cached SSD has to be dissociated from the HDD before it can be used to accelerate another HDD. Warning: Resetting the SSD will cause the data partition to be lost!

Acceleration can be safely disabled instantly in Enhanced Mode. In Maximized mode, disabling acceleration safely will take some time as the HDD has to be synchronized to the cache first.

Note also that only one accelerated pair per system is allowed.

 Intel Z68: The Best of Both Worlds

We had some problems with a certain combination of a beta RST driver and BIOS, whereby the accelerated pair would inevitably become dissociated after a reboot. While we haven't encountered this problem since updating to the final RST release (10.5.0.1027) and the latest BIOS for our MSI board, we would advise backing up data before using SSD caching, especially in maximized mode.