Which factor is NOT directly related to RAID level 1 functionality?

RAID level 1, also known as disk mirroring, focuses primarily on ensuring data redundancy and availability. In this configuration, data is duplicated across multiple disks, which means that if one disk fails, the other can instantly take over, thus ensuring that data remains accessible. This redundancy is crucial for high availability, making it a primary aim of RAID level 1.

While RAID level 1 does provide some level of performance improvement during read operations since data can be read from multiple disks simultaneously, this isn’t its main feature. The performance gains are incidental and vary based on workload, but they do not define RAID level 1's core functionality. Therefore, the improvement in performance is not a direct factor in RAID level 1's design or primary purpose.

User authentication is not related to RAID functionality at all, as it pertains to securing access to systems and data rather than how data is stored or retrieved in a RAID setup. Ultimately, the most accurate understanding of RAID level 1 revolves around its commitment to data redundancy and high availability, while performance and authentication are secondary or irrelevant aspects in this context.