Engineer F/M Dynamic Approximate Computing for Energy-Efficient AI Hardware Accelerators

Inria Rennes; Rennes; On-site; EUR 20,000 - 31,000; Full time

Job summary

Inria Rennes invites applications for a PhD researcher position focused on energy-efficient AI accelerators using approximate computing and hardware-software co-design.

You will investigate adaptive approximation techniques, develop modeling and prototyping workflows, and collaborate with a team to balance performance and accuracy. Strong HW/SW background and a Master’s degree are required; fluent English; Rennes, France.

Qualifications

• Master’s degree or equivalent in computer engineering or related field.
• Strong HW design and FPGA/ASIC flow experience.
• Proficient in C/C++, Python and Linux scripting.
• Familiarity with deep learning frameworks (PyTorch/TensorFlow).
• Experience with approximate computing techniques is a plus.

Responsibilities

• Investigate energy-efficient AI accelerators using approximate computing.
• Develop hardware-software co-design approaches.
• Model, simulate, and prototype with AI workloads.
• Collaborate with the team to balance performance and accuracy.

Skills

VHDL/Verilog

HW synthesis

Computer architecture

C/C++

Python

Linux scripting

ML frameworks

Approximate computing

Analytical skills

Communication

English proficiency

Teamwork

Open mindedness

Master’s degree requirement

Education

Master’s degree in Computer Engineering or related areas relevant to the PhD topic

Tools

PyTorch/TensorFlow

Job description

Context

Context and Background

As artificial intelligence expands across edge devices, data centers, and embedded systems, the demand for computational power has grown dramatically. Deep neural networks require billions of arithmetic operations and move vast amounts of data, which drives up both energy consumption and hardware complexity. Specialized accelerators like GPUs and TPUs have delivered significant improvements over general-purpose processors, yet the increasing scale of AI models continues to push power and thermal limits. This becomes particularly challenging for edge and battery-powered devices, where energy efficiency determines not just performance but practical viability and long-term sustainability.

Approximate computing offers a compelling approach to these energy constraints by trading some computational precision for improvements in power efficiency, performance, and chip area. The fundamental insight is that many AI applications, such as image recognition, speech processing, and recommendation systems, can tolerate a degree of error. Neural networks are particularly resilient, maintaining acceptable accuracy even when operations use reduced precision, simplified circuits, or probabilistic components. Leveraging this tolerance allows designers to reduce switching activity, memory bandwidth, and overall hardware complexity.

For AI hardware accelerators, approximate computing can be implemented across multiple design layers: algorithmic techniques like model pruning and quantization, architectural approaches such as approximate memory hierarchies, and circuit-level methods including approximate multipliers and adders. Together, these strategies can substantially reduce both dynamic and static power while keeping application performance within acceptable error margins. As AI deployment scales from resource-constrained edge devices to large data centers, approximate computing has become an essential research direction for achieving sustainable and energy-efficient acceleration.

Assignment

The primary objective of this job is to investigate and advance the design of energy-efficient AI accelerators by dynamically applying approximate computing techniques and to advance hardware-software co-design methodologies. The research will build upon recent advancements in efficient domain-specific architectures for AI. The goal is to develop novel approaches that balance performance, energy efficiency, and accuracy, while addressing the unique challenges of implementing approximate computing in real-world AI systems.

Main activities

This research explores the principles and practical implications of approximate computing as a pathway toward more energy-efficient AI hardware accelerators. It examines how different forms of approximation affect computational efficiency, prediction accuracy, and overall system-level performance. Rather than treating these techniques in isolation, the study considers their combined impact across the computing stack, with particular attention to how accuracy-efficiency trade-offs can be characterized and controlled.

A central theme of the work is the integration of hardware and software perspectives through a co-design approach. By closely aligning algorithmic characteristics with architectural features, the research aims to uncover strategies for embedding approximation mechanisms directly into accelerator designs. Emphasis is placed on adaptive and context-aware approximation techniques that can dynamically balance energy savings and output quality, ensuring that efficiency gains do not compromise application-level requirements.

To ground these ideas in practice, the research involves modeling, simulation, and experimental prototyping using representative AI workloads, including deep learning inference and computer vision applications. Through systematic evaluation and validation, the study aims to assess the feasibility, robustness, and scalability of proposed approaches, contributing insights into the design of next-generation energy-efficient AI systems.

Skills

Required Skills

• Strong HW design skills : VHDL/Verilog, HW synthesis flow (design, simulation, synthesis, and deployment through commercial tools for FPGA or ASIC)
• Strong foundation in computer architecture and Systems design. Knowledge about hardware architectures of Neural Network accelerators is a plus.
• Strong SW Programming/Scripting : C/C++, Python, Linux scripting
• Familiarity or Experience with machine learning fundamentals and Deep Neural Network development frameworks, e.g., PyTorch/TensorFlow
• Experience with approximate computing techniques (e.g., functional approximation, mixed-precision arithmetic, pruning) is a significant plus.
• Excellent analytical and problem-solving abilities, with an interest in optimizing for energy efficiency.
• Strong communication skills to articulate research findings clearly and effectively.
• Languages : proficiency in written English and fluency in spoken English are required.
• Relational skills : the candidate will work in a research team, where regular meetings will be set up. The candidate has to be able to present the progress of their work in a clear and detailed manner.
• Other values appreciated are open-mindedness, strong integration skills, and team spirit.
• Candidates must have a Master’s degree (or equivalent) in Computer Engineering or related areas relevant to the PhD topic.
• Talented last year Master’s students may start as 6-month interns and continue as Ph.D. researchers after graduation.