By their nature, SCSI drives have always provided low access times and high throughput at the expense of sheer capacity, as these qualities are of more value to servers than capacity.

Earlier this year, Seagate announced the Cheetah NS series. The 3.5” drive somewhat bridges the gap between the engineering problems of capacity and reliability that SCSI drives faced. It does this by reducing the spindle speed from 15,000 to 10,000 RPM while offering more storage capacity, delivered by employing PMR (perpendicular magnetic recording).

The good news is that its drive mechanism is derived from the 15,000 RPM Cheetah 15K.5 platform, so the NS series’ heritage is rooted in reliability. Combining the SAS drive mechanism with a slower spindle speed also reduces the amount of errors the drive is likely to encounter. It also reduces the power draw to a meagre 8 watts during operation, as well as reducing the operating temperature of the drive – a boon for already toasty server rooms.

The Cheetah NS supports dual port SAS controllers and can queue 128 tasks, in addition to the more mundand power saving features and head landing zones that are common to SAS drives. We tested a pair of Cheetahs with HD Tach and an Adaptec 31605 card and compared the results with the 2.5” 15,000 RPM Savvio line..

	MB/s	MB/s Burst	Response time (ms)
Savvio	96.6	196.2	5.6
Cheetah NS	84.3	502	7.5

As the capacity of the Cheetah NS is higher than the Savvio, more data passes under the read heads per rotation, leading to more impressive burst reads. As a result of this, the NS series would lend itself well to workstations dealing with high bitrate video, as well as more traditional servers and SANs.

Unfortunately, we can’t test the most important factor: reliability. However Seagate boasts a tenfold improvement in the rate of unrecoverable errors, and both the five year warranty and a quoted 1.4 million hours MTBF (mean time before failure) reflects Seagate’s confidence in the drives.

The Cheetah NS line is available in both Serially Attached SCSI (SAS) and Fibre Channel, and prices for the 400GB model are roughly at the $1000 mark. This will vary depending on what your reseller is prepared to do for you.