Cray versus Raspberry Pi

Summary

Please visit the sponsor! Cray versus Raspberry Pi 11 June 2025 I fondly recall the era when the pinnacle of supercomputing was the Cray 1. Even the shape of this computer was massively different to anything that came before and it was so futuristic that it could have come straight from a scifi movie. While almost all other computers of the 1970s were just a collection of huge rectangular cabinets with blinky lights and perhaps a few tape drives, the Cray 1 looked more like a piece of space-age furniture and seemed very small for what it was. Never the less, the Cray was a pretty hefty bit of kit, weighing in at over 5 tonnes (most of that being the cooling system) and consuming a staggering 115KW of electricity when its 64-bit processor was chugging along at 80MHz and interrogating the 8MB of memory it was attached to. Those numbers, and the 160MFLOPS of raw performance may have been mind-blowing "back in the day" but when you compare them to what we can buy today you'll likely be even more shocked. The Cray 1 cost an astounding US$8 million in 1977 which, if you adjust for inflation, is equal to more than US$40 million in today's dollars. Suffice to say that at that price, only around 100 or so systems were ever sold and they tended to be used for very specific scientific applications rather than as a general purpose computer. Let's jump forward about half a century to the present day and compare what was once the world's fastest computer to something far more modest -- by today's standards. The RPi5 is much smaller and lighter than the Cray 1, by many orders of magnitude. In fact we're talking just 50g versus 10 tonnes. The RPi5 uses far less power at around 12W versus the 115KW of the Cray. But what about performance? Can this tiny single-board computer match the awesome power of what was once the fastest computer on the planet? Well, as I mentioned earlier, the Cray had about 160MFLOPS of raw processing power; the Pi has... up to 30GFLOPS. Yes... that's *giga*F...