A forecast says Nvidia's rack-scale system Kyber, now under development, is unlikely to be launched by 2027.

CNBC, citing a report by SemiAnalysis, said Kyber, which was to be launched in 2027 with the Rubin Ultra chip, has slipped to 2028. CNBC said worries are growing over Nvidia's roadmap.

Kyber is a product that packs 144 of Nvidia's highest-performance chips into a single server cabinet so it can operate like one giant computer. It provides the computing power AI companies need to train and run the latest models.

The design increases density and reduces latency by placing GPUs vertically rather than horizontally in compute trays. Kyber was expected to launch in 2027 alongside Nvidia's next-generation rack-scale system, Vera Rubin Ultra.

The cause is cited as the extreme difficulty of manufacturing a specific printed circuit board, or PCB, used in Kyber.

SemiAnalysis said, "The Kyber NVL144 rack architecture has been delayed to 2028 due to PCB midplane manufacturability issues." A midplane is a multilayer printed circuit board that connects electronic modules within a system. SemiAnalysis said the large NVL576 system, which links 8 racks with fibre-optic cables, is also likely to be delayed or limited to small-scale production. Nvidia did not respond to CNBC's request for comment.

CNBC said the delay supports concerns that the pace of launching new products every year is colliding with manufacturing limits.

The report said an alternative plan to bundle 2 existing racks to deliver similar performance was also scrapped. Cloud customers rejected it, saying the design was cumbersome and operating costs were high. SemiAnalysis said, "Cloud service providers and hyperscalers strongly pushed back against the strange design and heavy operational burden, and it was ultimately cancelled."