Any storage peripheral that does not employ any method of buffering between the storage medium and the system interface will suffer in terms of poor I/O performance. E-Disk^® and E-Disk^® Altima^™ solid state drives employ a small amount of DRAM to serve as high-speed cache for implementing its write policies.

Given the volatile nature of DRAM, BiTMICRO developed DataSentinel to maintain standards of high performance without necessarily compromising data integrity. To reduce risk of data loss during low voltage and brownout situations, DataSentinel provides the following standard and user-programmable functions:

Low Voltage Detection

Input voltage sensors enable the E-Disk^® and E-Disk Altima^™ solid state drive to prevent data corruption or data loss due to unexpected power interruptions. As a precautionary measure, flushing of cache contents is initiated, and succeeding writes are directed to non-volatile storage immediately upon detection of non-critical low input voltage. Detection of critical low input voltage level halts all data-related operations until input voltage stabilizes. These reduce the risk of data corruption to file allocation (FAT) or translation tables in the event of an aborted write operation. Peripherals that do not have any low voltage detection logic are more exposed to data corruption because device writes are allowed to continue during low voltage conditions.

Redundant Pre-Write

The E-Disk^® and E-Disk^® Altima^™ solid state drive allocates a number of reserved memory blocks for use as a scratchpad and for internal translation tables. This BiTMICRO^® Networks proprietary feature pre-writes modifications to the translation tables to the scratchpad area.

Concurrent-Multiple Write

This feature reduces the risk of data and FAT corruption due to low voltage writes by reducing the "window of vulnerability" or window of time that the Flash device spends in the write phase.

Cache-on-Write Disable

When the user disables Cache-on-Write mode, data integrity is guaranteed because it is written directly to Flash memory before sending a positive acknowledgment to the host. There is however a severe penalty in write performance when selecting this mode. Read performance is not affected since read cycles still see the full cache size.

DataSentinel is a value-added feature in all E-Disk^® Altima™ solid state drives.