Promise Pegasus RAID R6 review

Thunderbolt peripherals finally arrive, but does this immense RAID drive impress?

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  • Blisteringly fast
  • Looks great next to a Mac
  • First Thunderbolt peripheral


  • Expensive

While the first Thunderbolt-equipped Macs appeared in February, dedicated peripherals have been a long time coming. Perhaps inevitably, the first to arrive are RAID drives, such as the Promise Pegasus RAID R6 we have here.

While the Thunderbolt port is capable of carrying data at up to 10Gbps in both directions, a single-drive external storage device is limited by its SATA connection, throttling speeds at 3Gbps, or 6Gbps if the less common SATA 3 is used.

But a RAID drive set up in a striped rather than mirrored array can draw data from more than one hard disk at a time, greatly increasing its overall speed.

The Promise Pegasus RAID R6 RAID drive has six bays, each preloaded with a 1TB, 3Gbps, 7200rpm SATA hard drive. It's pre-configured in RAID 5, which gives a total of 5TB of storage, but if any of your six drives fail, you can replace it without losing data.

When you first switch on it takes up to 10 hours to initialise itself, but unless you want to change the RAID setting you only need to do this once, and no user intervention is required. If you don't need quite so much storage, a four-bay unit is also available.

Both models are clearly built with the Mac user in mind; with their brushed aluminium finish and black trim, they're a perfect complement to the Thunderbolt-equipped computers in Apple's notebook and desktop range (the current release of any Mac except the Mac Pro).

We tested the Pegasus using QuickBench, which measures transfer speeds in megabytes per second. Taking an average of five tests, it achieved a random read rating of 240.745 MB/sec, and a random write speed of 229.124 MB/sec.

As it's Thunderbolt-only we can't make direct comparisons with other connectivity methods. But to give you an idea of just how fast it is, we also measured a perfectly capable FireWire 800 drive. Again averaging five tests, it achieved random read speeds of 15.505 MB/sec and random write speeds of 18.366 MB/sec.

At over £1,200 for a fully laden six-drive device, the Promise Pegasus RAID isn't a casual investment. But if you need fast transfer speeds, it doesn't disappoint.

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Tech Specs

Product TypeDAS Array
Number of Total Expansion Bays6
Total Hard Drive Capacity Installed6 TB
Number of Hard Drives Supported6
Number of Hard Drives Installed6
Brand NameApple
RAID Levels1, 5, 50, 6, 60, 10
Host InterfaceThunderbolt
Height251.5 mm
Width195.6 mm
Depth185.4 mm
ManufacturerApple, Inc
Product ModelH5186ZM/A
Product NamePromise Pegasus R6 DAS Hard Drive Array
Manufacturer Part NumberH5186ZM/A
Manufacturer Website Address
Marketing Information

Promise Pegasus R6 is the first six-bay high-performance hardware RAID solutions designed to unleash the raw power of Thunderbolt. Pegasus R6 features six 1TB 7200-rpm hard drives in a compact hardware RAID enclosure with Thunderbolt connectivity, delivering over 800MB/s of disk performance.

Package Contents
  • Promise Pegasus R6 H5186ZM/A DAS Hard Drive Array
  • Power Cable
  • Quick Start Guide
Limited Warranty2 Year
Weight (Approximate)9.20 kg