Possible storage efficiency with constant fault tolerance

The following figure shows a graph of Storage Overhead when the system's fault tolerance is held constant at 6. This means the system can tolerate up to 6 node outages or destructions without loss of data.

This system can tolerate up to 6 node outages or destructions without loss of data. Even with a fairly large IDA width of 12, the storage overhead is quite high at 100%. That is because this system corresponds to a "6-of-12" IDA Configuration. That is, IDA Width is 12, and Threshold is 6. However, as IDA Width increases and the fault tolerance is held constant at 6, the storage overhead rapidly falls. At the right-edge of the graph the IDA Configuration is a 30-of-36. This system can still tolerate up to 6 node outages or destructions, yet storage overhead has dropped to just 20%. This graph shows how the ability to use higher IDA Widths is critical to achieve good storage efficiency in a reliable system.