In a fitting tribute to the 50th anniversary of Apple’s founding and the first use of the Cray-1 supercomputer, the Museo de Historia de la Computación in Spain unveiled a Cray-1 replica built by repurposing 30 Mac Minis. The project took 18 months to build and is now open to the public.
At first glance, the idea of building a supercomputer replica with compute from vintage chips seems quite futile. However, one must remember that although the world’s first commercially successful supercomputer, the Cray-1 was first operational in Los Alamos in 1976. There is a huge gap in computing prowess of chips today and those that were launched a decade ago.
Imagine stretching this further to five decades with Moore’s Law in mind. Even if the computing prowess of a single modern-day chip might still be less than Cray-1, when you are putting together chips from 30 Mac Minis from 2012-14, the difference will become obvious.
A 9,375x jump
The museum team sourced 25 dual-core i5 units and five quad-core i7 units, bringing the total computation capacity of the replica device to 1.5 TeraFLOPS. In comparison, the original Cray-1 boasted peak capacity of 160 MegaFLOPS. This a still a 9,375x jump over the original supercomputer’s capabilities and shows how powerful chips have become over the years.
Nevertheless, Cray-1 was still an extremely popular system in its day and sold more than 80 installations during its time. It was extremely popular with science and engineering institutions that wanted to churn massive datasets to make accurate predictions in areas such as weather forecasting, aerodynamics and even nuclear physics.
Central to its ability to churn these numbers was not just the hardware but also how it processed the data. Cray-1 introduced the power of vector processing, where data was processed it parallel, saving precious time by avoiding the sequential processing that computers then did.
Improvements with a hint of nostalgia
Back in 1976, the Cray-1 supercomputer was cooled using a large network of refrigeration lines connected to a 20-ton refrigeration compressor located in a separate room. For the replica, though, the museum designers took a passive-cooling approach and built a vertical convection tower using aluminum trays and a steel chassis to dissipate the heat generated by the processors.
This passive approach removes the need for any mechanical fans to deal with the heat of the processors, making the replica extremely silent. The only noise coming from the system is that of the Ethernet switches at the base but the team plans to replace them with silent models soon too.
Instead of relying on Linux for distribution, the team chose Apple’s macOS Mojave (10.14) because it lets nodes in a cluster pass tasks to each other. Visitors to the Museum can even see the Cray-1 replica in action as it runs matrix algorithms and operates between single core and full suite to demonstrate its computing prowess.
The design team has also built a custom terminal looks like a historic relic from the 1970s but also has a Mac Mini embedded in to help connect with other cluster nodes. The original plans feature CRT monitors too but were eventually replaced by flat screens that offered simpler connectivity options.
The Museum may have taken a short cut here but is leaving no stone unturned to ensure that the Cray-1 replica finds its place in the TOP500 supercomputer list. For that, it might need another 70-80 Mac Minis but that shouldn’t be very difficult to source.