Promise Pegasus R6 review

The first Thunderbolt storage array is finally here and it blitzes through our benchmarks at astonishing speeds.

When the Pegasus was configured using a RAID level with more data redundancy, large files performance was generally a bit slower while small files performance was a bit quicker.

The RAID 0 performance of the Pegasus Promise R6 when fitted with six 1TB 7,200rpm hard disks.

The Promise Pegasus R6 is incredibly fast when configured as a RAID 0 array.

To see how much of this incredible performance was due to RAID rather than the Thunderbolt interface, we also tested the Promise R6 with just a single disk fitted. In this configuration large files were written at 176MB/s and read at 122MB/s. Small files were written at 169MB/s and read at 109MB/s. Even without the benefit of RAID, a Thunderbolt-connected disk is still clearly, if not so dramatically faster, than the alternatives. USB3 disks, for example, can reach 100-120MB/s when writing large files.

The performance of the Pegasus Promise R6 when fitted with a single 1TB 7,200rpm hard disk.

The Promise Pegasus R6 isn't as awe-inspiringly fast when fitted with just a single disk, but it's still fast.

Although the Pegasus R6 isn't available diskless or pre-fitted with solid state disks (SSDs), we wanted to see how just fast it could copy files when fitted with SSDs. We installed a pair of 240GB Kingston HyperX SSDs configured as a RAID 0 array. Although it was faster than a hard disk configuration in almost all of our tests, it wasn't dramatically quicker. Large files were written at 576MB/s and read at 596MB/s. Small files were written and read at around 208MB/s. The hard disk configurations did have the benefit of six disks though, where as our SSD configuration used just two SSDs. In any case we can't imagine too many SSD Thunderbolt arrays in actual use, if only because of the added expense on what is already a very pricy array.

The RAID 0 performance of the Pegasus Promise R6 when fitted with two Kingston 240GB HyperX SSDs.

The Promise Pegasus R6 is fast when fitted with a pair of Kingston HyperX 240GB SSDs, although not as breathtakingly quick as we were expecting.

So what's our verdict?


There's no doubt that thanks to Thunderbolt, the Promise Pegasus R6 is one of the fastest storage products we have ever seen. It's also very expensive, although its price per gigabyte of 18p, while high, isn't outrageously extortionate. However, even if you have the modern Macs required to use it, you'll need to transfer and manipulate seriously massive amounts of data regularly, such as HD or 4k video files or sprawling databases, to justify its high price.

SPECIFICATIONS Chassis: Desktop Storage: 6 x 3.5in 1TB 7,200rpm SATA2 hard disks in removable disk trays (not hot swappable) Array support: RAID 0, 1, 5, 6, 10 Network: 2 x Thundebolt Other ports: 1 x serial port Management: Promise Utility 3.16 Price per gigabyte: 18p Power consumption Idle 42W Active 50W BENCHMARKS RAID 0 Large write 590MB/s Large read 499MB/s Large average 545MB/s Small write 196.9MB/s Small read 104MB/s Small average 150.5MB/s RAID 5 Large write 482MB/s Large read 374MB/s Large average 428MB/s Small write 220MB/s Small read 111MB/s Small average 165.5MB/s RAID 6 Large write 494MB/s Large read 250MB/s Large average 372MB/s Small write 185MB/s Small read 113MB/s Small average 149MB/s RAID 10 Large write 344MB/s Large read 228MB/s Large average 286MB/s Small write 141MB/s Small read 148MB/s Small average 144.5MB/s SINGLE DISK Large write 176MB/s Large read 122MB/s Large average 149MB/s Small write 169MB/s Small read 109MB/s Small average 139MB/s RAID 0 SSD Large write 576MB/s Large read 596MB/s Large average 586MB/s Small write 209MB/s Small read 208MB/s Small average 208.5MB/s

Featured Resources

Key considerations for implementing secure telework at scale

Identifying the security risks and advanced requirements of a remote workforce

Download now

The State of Salesforce 2020

Your guide to getting the most from Salesforce

Download now

Fast, flexible and compliant e-signatures for global businesses

Be at the forefront of digital transformation with electronic signatures

Download now

Rethink your cybersecurity strategy for the new world

5 steps to secure the enterprise and be fit for a flexible future

Download now

Most Popular

How to find RAM speed, size and type

How to find RAM speed, size and type

3 Aug 2020
How to use Chromecast without Wi-Fi

How to use Chromecast without Wi-Fi

4 Aug 2020
How do I fix the Windows 10 Start Menu if it's frozen?
operating systems

How do I fix the Windows 10 Start Menu if it's frozen?

3 Aug 2020