If you head over to the Promise Pegasus product information page you’ll notice that it is the first RAID storage to use Apple’s new Thunderbolt port.
It requires Mac OS X 10.6.6 or higher and of course the Thunderbolt technology port.
The features include either 4BT, 6TB, 8TB or 12TB of storage and supports RAID types 0, 1, 5, 50, 6, 60, and 10. It has two Thunderbolt ports so you can daisy chain to a display or other Thunderbolt capable devices. Like most modern RAIDs it is also capable of hot swapping hard drives and is Time Machine compatible.
It comes in two models, the R6 and R4. The R6 has 6 drive bay slots and the R4 comes with 4.
They will be available in Apple retail stores in Q2 2011. No pricing has been announced.
Promise Pegasus: The First RAID Storage to Use Apple’s Thunderbolt Technology
When Apple introduced Thunderbolt technology in early 2011, it marked a major turning point for high-speed data transfer and external storage performance. Designed in collaboration with Intel, Thunderbolt delivered an unprecedented combination of speed, flexibility, and daisy-chain support—all through a single compact port. The first storage solution to take advantage of this cutting-edge interface was the Promise Pegasus series, a powerful desktop RAID system engineered for creative professionals, power users, and anyone who needed vast, reliable, and ultra-fast storage.
Promise Technology was already known for its enterprise-grade RAID solutions, but with the Pegasus line, the company pushed the boundaries of what external storage could be. The Pegasus RAID became a showcase product for Thunderbolt, demonstrating that the new port was not just a faster connection—it was a transformative leap for workflows involving massive files, high-definition media, and data-intensive tasks.
Thunderbolt + RAID: A New Era for High-Performance Storage
The Promise Pegasus was designed from the ground up to harness the speed of Thunderbolt, which combined PCI Express (PCIe) performance with DisplayPort capabilities. This allowed storage units like the Pegasus to deliver data transfer rates drastically faster than USB 2.0, FireWire 800, and even first-generation eSATA connections.
Thunderbolt’s ability to handle dual-channel 10Gbps bandwidth (20Gbps total) meant that RAID arrays could finally operate without common bottlenecks found in older external interfaces. The Pegasus could move large files—such as uncompressed HD video, raw photos, audio projects, and entire system backups—at speeds previously only possible inside a computer’s motherboard.
For content creators, this meant editing directly from the RAID was no longer just possible—it was seamless.
System Requirements and Compatibility
To use the Promise Pegasus, Apple required users to be running:
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Mac OS X 10.6.6 or later
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A Mac equipped with the new Thunderbolt port
At the time, early 2011 MacBook Pros were the first machines to include Thunderbolt technology, with iMacs and Mac minis following shortly after. This made the Pegasus one of the earliest real-world demonstrations of Thunderbolt’s capabilities.
The device also supported Apple’s Time Machine, making it a strong choice not only for professional editing workflows but also for advanced backup setups.
Massive Storage Options for Every Workflow
Promise offered the Pegasus in multiple storage capacities to accommodate different user needs. Early available configurations included:
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4TB
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6TB
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8TB
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12TB
These capacities were made possible by combining multiple hard drives in either the R4 (four-bay) or R6 (six-bay) enclosure models. For users who required more storage or greater redundancy, the R6 provided additional flexibility and performance.
Because the Pegasus was a hardware RAID system, users could rely on the dedicated RAID controller built into the device, reducing strain on the host Mac and delivering consistent, high-speed performance.
Supported RAID Levels: Flexibility for Any Scenario
One of the most impressive aspects of the Promise Pegasus system was its support for a wide array of RAID configurations. This allowed users to tailor the storage system to their workflow, whether they prioritized speed, redundancy, or a combination of both.
The Pegasus supported the following RAID levels:
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RAID 0 – Striping for maximum performance
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RAID 1 – Mirroring for strong data protection
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RAID 5 – Balanced performance and redundancy
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RAID 50 – High performance + distributed parity
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RAID 6 – Double-parity protection for critical data
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RAID 60 – RAID 6 across multiple arrays for high-capacity, fault-tolerant configurations
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RAID 10 – Mirrored stripes for high-speed redundancy
This list of options was significantly broader than what was offered by most consumer RAID systems at the time. Professionals working with 4K video, large graphic design libraries, and music production projects could tailor their Pegasus to match their exact performance and safety requirements.
Dual Thunderbolt Ports: Daisy-Chain Your Workflow
Another standout feature was the inclusion of two Thunderbolt ports, allowing users to daisy-chain multiple Thunderbolt devices. This was an important milestone, showcasing how Thunderbolt could carry massive amounts of data while also passing through video signals to displays.
In practice, this meant users could:
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Connect the Pegasus RAID to a Thunderbolt-equipped Mac
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Then connect a Thunderbolt display, another RAID unit, or additional Thunderbolt-ready devices—up to six devices on a single chain
For professionals with complex workstation setups, this daisy-chain capability simplified cabling and offered much cleaner connectivity.
Hot-Swappable Drives for Maximum Uptime
The Promise Pegasus supported hot swapping, meaning drives could be replaced or upgraded without shutting down the entire system. This is particularly important in environments where downtime means lost productivity—such as video editing studios, backup stations, and server rooms.
If a drive failed in a RAID-protected configuration (such as RAID 5, 6, 50, or 60), the array could remain operational while the failed drive was replaced. The system would automatically rebuild data onto the new disk, helping maintain workflow continuity.
R4 vs. R6: Which One Was Right for You?
Promise offered two main models:
Pegasus R4 (4-Bay Model)
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Ideal for smaller projects, individual creators, and users transitioning from single-drive or dual-drive external storage
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Balanced performance with fewer drives to manage
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Supported RAID 0, 1, 5, and 10
Pegasus R6 (6-Bay Model)
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Designed for professionals handling large-scale media
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Additional drives meant higher speed, more storage, and greater RAID flexibility
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Supported high-end RAID modes like RAID 6 and RAID 60
Both models were engineered with the same rugged metal chassis, optimized cooling systems, and professional-grade performance standards.
Availability and Pricing
Promise Pegasus units were scheduled to be available in Apple Retail Stores in Q2 2011. At the time of the announcement, pricing was not yet revealed. Apple and Promise later positioned the Pegasus line as a premium storage product, reflecting the advanced technology and professional-grade performance delivered through Thunderbolt.
Although prices were eventually set at the high end of the consumer storage market, professionals in video editing, 3D rendering, scientific computing, and enterprise environments found the Pegasus to be a worthwhile investment due to its reliability and speed.
A Milestone in External Storage Innovation
The Promise Pegasus series remains a historic milestone in the evolution of external storage. As the first RAID system to leverage Thunderbolt, it demonstrated the port’s potential and accelerated mainstream adoption of high-performance external workflows for Mac users.
Its introduction helped shape the future of desktop storage for years to come, influencing how manufacturers approached connectivity, speed, and the concept of second-generation RAID systems.
