RAID 6 uses dual parity to provide fault tolerance, which requires additional calculations during write operations. This introduces a write penalty, as the system must compute and write two sets of parity data for each write operation, leading to slower write performance compared to other RAID levels.

Insufficient storage on the RAID controller:Would affect storage capacity, not write performance.

High read I/O load on the array:Impacts read performance, not write performance.

Increased network latency:Affects data transfer times but not the internal write operations of the RAID array.

Write penalty associated with dual parity calculations:The most likely cause of slow write performance in RAID 6.