Flash Module with DRAM Buffer

The purpose of designing an additional DRAM chip into the flash module is to increase both performance and endurance.

Performance :

A DRAM chip in a flash module has exactly the same function as a cache in a hard disk.  Whilst the flash module is in operation the controller throws small data into the DRAM chip for immediate responses; the DRAM chip acts as a directory that assists the controller to allocate data to the assigned positions.  Therefore it shortens the response time and increases the performance.

Endurance :

Comparing Flash Storage to DRAM, DRAM does not have any limitation of program/erase cycles, whereas Flash Storage does.  Every time when the controller tries to program a sector of data into Flash Storage, it needs to erase a whole block of Flash before re-programming it.  However with the DRAM buffer small data can be collected to a certain amount before delivering to the Flash Storage which reduces the program/erase times to the flash chips, and therefore increases the endurance.