Japanese user's guide for the Sonnet Fusion R400Q 4-drive Serial ATA rack mount storage system with quad interface. These directions apply to storage systems with drives.
The Fusion D400Q and R400Q must have a hard drive in drive bay 1 when connected via USB, FireWire, or FireWire 800. This requirement is due to the Oxford bridge chip that controls USB and FireWire connectons. Drive bay 1 is the top bay in the Fusion D400Q and the left bay in the Fusion R400Q. As long as there is a drive in drive bay 1, bays 2-4 are unconstrained.
Note: This requirement does not apply to a direct SATA connection, which has no drive bay population requirements.
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.
