User's guide for the Sonnet Fusion R400Q 4-bay Serial ATA rack mount drive enclosure with quad interface. These directions apply to storage systems without drives.
Sonnet engineering has fixed this issue with some Fusion storage systems. This issue was addressed and fixed as follows:
APRIL, 2008: in Fusion D400Q and Fusion D500P systems with serial numbers beginning with J.
MAY 20, 2008: In Fusion D800RAID with serial numbers beginning with G.
All versions of Fusion R400Q and R800RAID are compatible with Seagate ES.2 Drives.
Note: Seagate ES.2 drives have lower performance than Sonnet recommended drives.
Another manufacturer's previously-installed SATA driver may be accessing a Sonnet SATA card in error causing a drive access slowdown. For example, we have seen Fusion D400QR5 performance drop from 200MB/s to under 50MB/s in such circumstances. The solution is to remove the other manufacturer's SATA driver.