Product Reviews

It's easy to understand the popularity of Serial ATA. It offers the best combination of cost, performance and capacity. However, although the slimmer SATA cables are easier to deal with than IDE and SCSI, when you get up to a dozen ports things can get messy. We found this in Evesham's SilverSTOR iSAN 1600SA.

3ware's 9500S multilane controller aims to remedy this cable-related clutter by amalgamating its 12 SATA interfaces into three InfiniBand ports. Located on the card edge, each one uses a much larger socket and the supplied cables have locking clamps at each end to stop them coming loose. Obviously, the receiving end also needs to have a multilane connector, and for testing we used a Chenbro 3U rack server equipped with 12 hot-swap drive bays connected to triple SATA backplanes, each sporting a single multilane port. 3ware also offers breakout cables with four individual SATA connectors at one end.

Configuration starts during system bootup, where a simple BIOS screen allows you to create, delete, modify or rebuild arrays and add a hot-standby drive to an existing array. The card can manage RAID0, 1, 5, 10, and 50 arrays, but JBOD configurations are no longer supported and won't appear

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as available units to the OS. For the latter, 3ware now uses the concept of single disk units, which can take advantage of features such as caching.

For testing, we installed Windows Server 2003 on a mirrored pair of 36GB Western Digital Raptor drives, and created a separate data partition on a quartet of 200GB Maxtor units configured as a RAID5 array with hot-standby. This took just over four hours to initialise. We also installed the drives in a physical pattern that ensured all three multilane ports were being used. Performance was on a par with 3ware's standard 12-port controller. Using the open-source Iometer, we saw rates of 123MB/sec for read operations on the RAID5 array using two workers, 64KB request sizes and ten outstanding I/Os, while the mirrored array returned 71MB/sec. Processor utilisation also remained down at under 9 per cent. We saw single drive performance settle at 52MB/sec, which rose to 164MB/sec with four drives and workers. With the Maxtor drives reconfigured as a Windows-managed RAID5 array, we re-ran Iometer and watched processor utilisation shoot up to nearly 17 per cent, clearly showing the benefits of hardware-based RAID.

Management options abound. 3ware's 3DM software allows the controller to be managed locally and remotely using a browser. The interface provides the same access to the drives as the BIOS menu, but you can also monitor errors, schedule regular array rebuilds, and ask for alerts to be sent to an email address.

There's no doubt the multilane interfaces make for a much tidier system when a large number of SATA drives are being used. Performance and costs are virtually the same as for the standard controller, but a glance at 3ware's website reveals that only four vendors currently produce suitably equipped chassis.