Relativity Networks raises $22 million to bring a faster kind of fiber to data centers
Relativity Networks, a startup developing hollow-core fibre optic technology, has raised $22 million in SAFE note funding to help data centre operators overcome the physical distance limits that increasingly constrain the AI compute boom. As firms spend heavily on ever-larger data centre campuses, network latency between distant clusters of GPUs has become a growing bottleneck, and faster fibre could allow developers more flexibility in where they build.
The funding round was led by Rhapsody Venture Partners, Bell Ventures Inc. and Faster Than Glass LLC, and the company also secured a separate $40 million follow-on order from an unnamed hyperscaler. Unlike conventional fibre, which transmits light through glass, hollow-core fibre sends it through a vacuum channel, cutting transmission time from around five microseconds to three and a half microseconds per kilometre — a 30% speed gain that CEO Jason Eisenholz says could let operators link data centres across 30% greater distances before latency becomes a problem, particularly for multi-campus deployments.
- Relativity Networks raised $22m for faster "hollow-core" fibre optics.
- Also won a $40m order from an unnamed hyperscaler.
- Tech cuts fibre latency by 30%, easing data centre siting constraints.
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Relativity Networks is a startup working on a new type of fibre optic cable used to connect data centres, the large facilities packed with computer servers that power the internet and, increasingly, artificial intelligence. Rather than sending light through solid glass, as standard fibre does, its "hollow-core" fibre sends light through a vacuum-filled channel, which lets signals travel faster. The company has just raised $22 million from investors to develop this technology further.
The demand for this comes from the rapid growth of AI, which requires vast numbers of computer chips working together, often spread across multiple buildings or sites. When these sites are far apart, the time it takes for data to travel between them can slow the whole system down, a problem known as latency. Companies building AI infrastructure are therefore looking for ways to link distant data centres without losing speed.
Relativity Networks' investors include Rhapsody Venture Partners, Bell Ventures and Faster Than Glass, and the firm has also won a separate order from a major cloud computing provider. The broader context is the enormous sums currently being invested in data centre infrastructure to support AI, with companies competing to solve the technical constraints, such as distance and speed, that limit how this infrastructure can be built.