Qblox reports achieving roundtrip latency below 4.0 microseconds on an NVIDIA RTX PRO 6000 Blackwell when integrated with the Qblox Cluster, a key threshold for real-time hybrid quantum-classical computing. The company integrated NVIDIA DGX Spark with a quantum system controller using NVIDIA NVQLink, also demonstrating 7.2 µs latency and bringing GPU acceleration directly into the real-time control loop, the company says.
“Quantum computers will scale only as fast as the classical control systems around them,” said Niels Bultink, CEO and Co-founder of Qblox, adding that these developments allow GPUs to become part of that control loop.
Qblox Cluster Achieves Sub-4µs Latency with NVIDIA RTX PRO 6000 Blackwell
The Qblox Cluster has been integrated with multiple NVIDIA GPUs, enabling real-time control for hybrid quantum-classical computing with roundtrip latency below 4.0 µs on NVIDIA RTX PRO 6000 Blackwell and below 7.2 µs on NVIDIA DGX Spark. This benchmark demonstrates a significant reduction in the delay between sending control signals to a quantum processor and receiving a response, a longstanding bottleneck in scaling quantum systems.
The integration uses NVIDIA’s NVQLink to facilitate this speed, allowing for GPU acceleration directly within the quantum system’s control loop. This means calibration routines can now adjust qubit parameters during experiments, rather than requiring pauses between them for updates. Qblox also measured roundtrip latency below 7.2 microseconds on NVIDIA DGX Spark, indicating the scalability of this low-latency control system beyond a single desktop GPU.
The integration enables support for real-time hybrid quantum-classical applications, with a single desktop system that can host quantum, AI, and simulation workloads via NVIDIA CUDA-Q . According to Qblox, the company’s Q1 sequence processors and LINQ architecture deliver the necessary throughput and low latency for smooth interaction with the GPU. GPU-accelerated decoders can now process syndrome data with minimal delay, improving the speed and accuracy of real-time error correction.
This achievement builds upon previous collaborations between Qblox and NVIDIA, including work announced in October 2025 and March 2026, and represents a transition from architectural design to verified hardware performance, according to the company. Niels Bultink, CEO and Co-founder of Qblox, said, “With these developments, the GPUs become part of that control loop, giving quantum systems access to the computing power they need in real time.”
DGX Spark puts an AI supercomputer on a quantum researcher’s desk.
Sam Stanwyck, director of quantum product at NVIDIA



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