Riding the SATA wave

InfoWorld’s recent review of SATA (Serial ATA) controllers concluded that those cards are ready for enterprise deployment, although there are differences among different vendors and models (infoworld.com/125). Can we say the same for SATA disk drives?

The short answer is: It depends on the application you plan to support. SCSI and FC (Fibre Channel) are still the best bet for critical applications. But the exceptional capacity and low cost per megabyte make SATA — and parallel ATA — drives a more cost-effective choice for applications that, for example, perform online backups or store reference data.

In fact, major vendors such as EMC, StorageTek, and Network Appliance are deploying SATA or parallel ATA drives for those types of applications, so why shouldn’t you?

Putting SATA to the test

Most SATA drives are essentially similar to their parallel-interface siblings, designed to handle the less demanding requirements of desktops and small workgroup servers. Many of the drives tested in this review are best suited to these types of specific responsibilities.

Western Digital is the exception, being the only vendor (at review time) that has developed enterprise muscles for a SATA drive, the WD Raptor. But it’s important to remember that Western Digital is also the only vendor in the group that doesn’t offer a line of SCSI drives: The WD Raptor is Western Digital’s waving flag to attract more enterprise buyers.

When it comes to disk drives, the aspects that matter to a potential buyer are performance, capacity, reliability, and cost. I tested the drives’ performance from an enterprise-deployment perspective, using Iometer 2003.2.15 to simulate typical server loads and recording the number of I/O operations per second that each drive was able to sustain for each test.

I then used a second Iometer script to measure the maximum transfer rate. I ran each script for 2 minutes, excluding the first 6 seconds of activity, and recorded the final average results. To test performance under stress, the server-load simulation test involved different data transfer sizes, varying from 512 bytes to 64KB, discretely scaled according to a commonly accepted pattern for file-server load.

For each data transfer size, the script created a composite mix of random disk accesses,  splitting I/O operation between reads and writes with an 8-2 ratio. I also ran the 73GB Fujitsu MAS3735NP — a fast-performing SCSI 320 unit — through the same tests for comparison.

A glance at the server-load simulation results  shows that the four SATA drives tested — the Maxtor Diamond Max Plus 9, Western Digital WD Raptor, and Seagate Barracuda Serial ATA V and Barracuda 7200.7 — all have strengths in different areas. Choosing the right one for your particular needs will depend on which quality is at the top of your list: fast data transfers, server  performance, reliability, capacity, or cost.

Maxtor Diamond Max Plus 9: Capacity leader

Maxtor offers SATA versions of its Diamond Max Plus 9 in 60GB, 80GB, 120GB, 160GB, and 200GB sizes, easily satisfying just about any capacity demand. The Diamond Max Plus 9 mounts both legacy and SATA power connectors, which can save a hasty trip to the local computer shop to buy those (thankfully inexpensive) adapters.