The shingled technology drives from Seagate have been the subject of a lot of conjecture about just how well they might perform in an UnRAID array.    There are some significant design constraints which could have serious consequences in write performance, as entire bands of data have to be re-read and then re-written just to update a single sector within those bands ["shingled bands"].    However, Seagate's design has taken these factors into account and they've built-in some mitigations design