ELT-scale Adaptive Optics real-time control with the Intel Xeon Phi Many Integrated Core Architecture

TL;DR

This paper demonstrates that the Intel Xeon Phi KNL architecture can effectively handle the high computational demands of ELT-scale adaptive optics real-time control, achieving high frame rates with minimal jitter.

Contribution

The study shows that the Xeon Phi KNL architecture is capable of real-time ELT-scale AO control at high frequencies with low jitter, advancing the hardware options for next-generation telescopes.

Findings

Achieved over 1.0 kHz control loop with <20 μs RMS jitter.

Processed camera frame-rate at up to 966 Hz with stable jitter.

Validated Xeon Phi KNL as suitable for ELT AO real-time control.

Abstract

We propose a solution to the increased computational demands of Extremely Large Telescope (ELT) scale adaptive optics (AO) real-time control with the Intel Xeon Phi Knights Landing (KNL) Many Integrated Core (MIC) Architecture. The computational demands of an AO real-time controller (RTC) scale with the fourth power of telescope diameter and so the next generation ELTs require orders of magnitude more processing power for the RTC pipeline than existing systems. The Xeon Phi contains a large number (> 64) of low power x86 CPU cores and high bandwidth memory integrated into a single socketed server CPU package. The increased parallelism and memory bandwidth are crucial to providing the performance for reconstructing wavefronts with the required precision for ELT scale AO. Here, we demonstrate that the Xeon Phi KNL is capable of performing ELT scale single conjugate AO real-time control computation at over 1.0 kHz with less than 20 {\mu}s RMS jitter. We have also shown that with a wavefront sensor camera attached the KNL can process the real-time control loop at up to 966 Hz, the maximum frame-rate of the camera, with jitter remaining below 20 {\mu}s RMS. Future studies will involve exploring the use of a cluster of Xeon Phis for the real-time control of the MCAO and MOAO regimes of AO. We find that the Xeon Phi is highly suitable for ELT AO real time control.