HPC innovation: fibre immersion.

HPC innovation: fibre immersion.

At DUG we pride ourselves on our innovation and cutting-edge technology, investing continuously in research and development to keep us at the forefront of the latest techniques and ideas. It’s how we’ve been able to design and build some of the most powerful and greenest data centres in the world. It’s evidenced by our patented DUG Cool immersion cooling system. And it’s why we’ve been internationally awarded at the 2019 DCD Awards for the best Enterprise Data Centre Design. 

One of the challenges for immersion cooling has been the inability to reliably immerse fibre-optic transceivers and cables.  The immersion fluid gets between the laser transmitter and the glass fibre, preventing the light from correctly entering the fibre, thereby rendering the cable “broken”.

This issue has subtle knock-on effects as to how you architect your network.  If you want 100Gb/s networking, and require copper-cables for your servers, then they are limited to a maximum of 4.5m in length.  This dictates that your high-performance switches have to be within 4m of your servers to achieve maximum speed and lowest latencies.  It also prevents you from immersing the switches.  Whilst you can easily have a high-performance switch located at the tank (rack), the spine of the network is typically located at a distance, requiring fibre connections.  As a result your switches need to have fibre-optic cable uplinks which prevents them from being immersed.

This has been a frustration we have been working around, but recently our R&D team solved the problem!

This node has been running in production using an immersed optical transceiver and fibre-optic cable for a number of days with no performance or reliability impacts. Testing is continuing but the team is optimistic: the completely silent data-centre is now possible!

By Stuart Midgley

Stuart Midgley is DUG's CIO and self-confessed "mad scientist". He holds a PhD in theoretical physics and is a world expert in high-performance computing. Stuart designed and developed the DUG Cool system of immersive cooling technology and was instrumental in the construction of DUG's world-class greenest data centres on earth. He's just as handy behind a BBQ. After all, he owns 17 of them.

DUG Technology