IBM's Nighthawk r3 to pack 520 qubits on road to 2027 system

IBM has taken the wraps off the Nighthawk r3, a forthcoming quantum processor carrying 520 qubits, according to The Register. The chip is positioned as a stepping stone toward a fault-tolerant machine the company aims to deliver in 2029.

The announcement follows closely on the release of Nighthawk r2, which became available in September with 120 qubits and support for circuits running 7,500 operations.

IBM says the r3 will hold more than four times the qubit count of its predecessor while handling 10,000 quantum operations, letting it take on bigger and harder problems without giving up speed or accuracy.

The r3 is scheduled for 2027. That is the same year IBM intends to join two of the processors into one system carrying over 1,000 qubits.

Linking the chips depends on 10 chip-to-chip interconnects known as l-couplers. IBM says the technology was trialled on earlier Nighthawk r1 hardware and will be used to build a single 1,040-qubit machine.

IBM argues that demanding applications increasingly call for circuits that run thousands of operations across roughly 100 qubits or more. Faster execution speeds up the gathering of the millions or billions of samples such computations require, which IBM says decides whether heavy workloads finish in a practical time and at a sensible cost.

The longer-term target is Starling, a processor IBM has said should reach reliable error-corrected operation in 2029. IBM now describes it as intended to be the first fault-tolerant quantum computer, running circuits of 100 million operations on 200 logical qubits.

That is a steep ambition. Fault-tolerant quantum computing has long been portrayed as roughly a decade off, though some in the industry see better odds as work on quantum-resistant encryption gathers pace. A University of Auckland professor said last year that quantum machines had not factored any number above 21 without resorting to shortcuts.

IBM laid out a Starling framework in a 2025 paper describing hardware for bivariate bicycle quantum low-density parity check codes, which it says cut the physical qubits needed to hold and process quantum information compared with surface codes. Under that design, Starling would be built from modules each holding a quantum memory and a logical processing unit, joined through universal adapters using l-couplers.

IBM is also pairing quantum hardware with classical high-performance computers to study error correction. Oak Ridge National Laboratory announced such a setup last week, and IBM has a partnership with Japan's RIKEN institute involving the Fugaku supercomputer.