The E-Waste Column no. 202

Jun 17
3 min read

Today, we are looking at a small datacenter that researchers created out of old phones.

🌱 How did researchers turn old phones into a small datacenter?

Researchers from the University of California San Diego worked together with Google to recycle old Google Pixel smartphones. They produced “a fully working computer cluster” out of the old phones, effectively giving them “a second life as a low-cost data center” or a “general-purpose computing platform”. To do this, the researchers began by stripping the old phones of what they called the “non-essential components”, which – amongst others – included the batteries, cameras, chassis, displays, and speakers of the phones. Once they were effectively left with only the motherboards and the system on chip (SoC), they replaced the Android operating system on these “with a general-purpose Linux distro used in data center applications” so that they could install new software (including Kubernetes) on the motherboards. They then created clusters using the motherboards of 20 to 50 phones.

🌱 What was the motivation behind this?

The fact that people swap out and replace their phones every few years is a large contributor to e-waste globally. In light of this, the project aimed to tackle e-waste. It, however, also aimed to find a way to decrease the environmental impacts and carbon emissions from electronics manufacturing by reusing parts rather than producing entirely new ones. The idea was to effectively reduce both the amount of e-waste being produced and the demand for new server hardware, by using e-waste as a source for parts.

🌱 How did the computer cluster compare to a modern server?

To show what potential capability old phones and devices still have, the researchers compared the performance of their system with that of a modern server’s central processing units (CPUs). Their results showed “that 25 to 50 old phones were equal to the computing power of a single dual-socket server-class CPU”. Moreover, they found that “smartphones from just three years ago [could] still deliver a higher single-core performance compared to servers like the Asus RS720A-E11, which can be equipped with Nvidia H200 or Nvidia RTX Pro 6000 GPUs and two AMD EPYC server processors, that you frequently find in the most powerful data centers”.

🌱 What could the computer cluster be used for in practice?

While the old smartphones were “unable to compete on a multi-core basis”, the researchers found that “the single core performance could exceed that of modern server CPUs”. In other words, “when running basic software configurations, older smartphones c[ould] outperform modern server CPUs when running individual tasks”. In their tests, the researchers could scale the cluster to 25 phones, with “good scaling characteristics” while running standard microservices. Effectively, their 20-phone cluster could, therefore, “support one application that a 75+ student class requires”. This means that “instead of hosting [the application] on the cloud, which would entail additional costs and resource use on the data center side, it could instead run these apps on a local deployment of these used smartphones”. The researchers are hoping to create a larger computer cluster, consisting of around 2000 phones, next. Through this, they want to create a local data center, which could support “a hundred [75+ student] classes at once”. The researchers say the advantages of this are that they can run apps locally and own the hardware needed for this. Moreover, all this is possible at a “fraction of the usual cost” normally needed to build a local server made from new components.