Nevertheless, firmware revision 0309 is available for all four M4 SSD capacities (64GB, 128GB, 256GB, and 512GB) and includes the following fixes, according to Crucial's release notes:
- Changes made in version 0002 (m4 can be updated to revision 0309 directly from either revision 0001, 0002, or 0009)
- Correct a condition where an incorrect response to a SMART counter will cause the m4 drive to become unresponsive after 5184 hours of Power-on time. The drive will recover after a power cycle, however, this failure will repeat once per hour after reaching this point. The condition will allow the end user to successfully update firmware, and poses no risk to user or system data stored on the drive. This firmware update is STRONGLY RECOMMENDED for drives in the field. Although the failure mode due to the SMART Power On Hours counter poses no risk to saved user data, the failure mode can become repetitive, and pose a nuisance to the end user. If the end user has not yet observed this failure mode, this update is required to prevent it from happening.
Crucial says if you're using a SAS Expander, do NOT this particular firmware and hang tight until it releases a compatible update (no time frame was given).
You can download the firmware here.