Wear Unleveling under Unbalanced Page Endurance in NAND Flash

Wear Unleveling: Improving NAND Flash Lifetime by Balancing Page Endurance on FAST 2014.


The start point of this paper is the observation that the various pages that constitute a block deteriorate at significantly different speeds. This paper use relief cycle to address this problem.

We define a relief cycle on a page the fact of not programming it between two erase cycles.

Two Relief Plan studied:

  1. The reactive approach use the correlation between a page position in a block and its endurance and relieve the weakest pages from the very first writes to the device.
  2. The proactive technique detect the weak pages on the go.


Results shows that the proactive technique is more efficient than the reactive one.