Sonnet Fusion D400Q review

Storage solutions come in many shapes,sizes, connection formats and speeds.

Unlike most, however, the Fusion D400Q from Sonnet Technologies actually comes in multiple connection formats and speeds at once. This is a four-drive Raid storage device with hot-swappable drive trays and a hinged panel at the front, with a suite of connection options at the back.

Whether you want to connect using USB 2, FireWire 400, the higher-speed FireWire 800, or eSata (external Sata), this drive has what you need. You're unlikely to swap back and forth a lot, but it does mean that you can connect it to any machine you like. This is really best used with an eSata PCI card, as that's what will give you the best performance. But if you need to connect to another Mac using either flavour of FireWire or even USB, you're free to do so.

And this is where the variety of speeds comes in. Sata is designed as a very high-speed interface and, in our tests with this interface and the unit configured as Raid 0, it managed a sustained throughput of 63MB/sec with bursts of upto 135MB/sec.

When we switched to FireWire 800 and ran the tests again it did well, but not quite as well as that; it reached a sustained 33.1MB a second and peaked at 53MB/sec. Switching to the FireWire 400 connection showed a slight drop again, to 33MB/sec dead for the constant throughput and a peak of 36.9MB/sec. Finally, the USB performance was the slowest of the lot, which was exactly what we expected. Our sustained throughput test managed 16MB/sec, and it reached peaks of 17MB/sec. This is significantly less than USB 2's theoretical maximum, but it isn't unusual in real-world USB performance.

With test results like these it is pretty clear what interface you should use. Of course, Macs don't come with eSata ports as standard, so you'll need to add a PCI card such as the Sonnet Tempo Sata X4P that we used for our tests. It doesn't need a separate Sata port for each drive, and it works well with PCI-X-based Power Mac G5s as well as PCI-Express machines.

The connections at the back all route through its internal Sata controller, whichever ports you actually choose to use. When using the FireWire or USB connections, you have to use the supplied 6in Sata 'loop-back' cable to connect its out-bound port to its in-bound port, or you won't be able to connect. At this point we should mention that you can't use more than one connection at once. Doing this won't cause a catastrophic failure, but you won't be able to mount or use the drives until you remove all but one connection. Most importantly, this means that you don't need to reformat the drives to use a different interface.

As a Raid-ready device, the four hard disks are on removable trays, each individually lockable. We used the Raid features in Apple's Disk Utility to set up a number of different Raid configurations, all without hassle. We did notice one thing that was a little disconcerting, although it wasn't a serious issue. The time from powering up the Fusion to when the disks mounted was unusually long. It took about a minute before the drives responded, then it took a few more seconds before the volumes mounted. However, from then on the performance was as good as the selected interface could manage.

The fan in the device was noticeable only in its silence; it was exceptionally quiet when in use, so it should do well in quiet offices. The Fusion D400Q is an excellent choice for anyone who needs high-speed data transfer, both in bursts and sustained streams. The delay in mounting was a little odd, but we didn't note any other issues.