Artificial intelligence (AI) is transforming the world in unprecedented ways. However, AI poses significant challenges for computing systems, as it requires massive amounts of data and computation to achieve high accuracy and functionality.
Researchers and engineers, in response to the increasing demand for AI, have been developing a variety of hardware accelerators—specialized devices that can speed up AI workloads and reduce power consumption.
In this article, we will explore some of the key concepts, developments, and controversies related to hardware accelerators for AI.
What are Hardware Accelerators ?
Architecture of Hardware Accelerator
A hardware accelerator is a specialized piece of hardware designed to offload and accelerate specific tasks or functions, typically in the context of computing or processing. Unlike a general-purpose central processing unit (CPU), which is versatile but may not excel at certain types of computations, a hardware accelerator is optimized to perform specific operations more efficiently.
A hardware accelerator can design custom instruction sets tailored for specific AI algorithms, like convolutional neural networks (CNNs), operating at different levels of abstraction, including instruction set, algorithm, or application.
Alternatively, a hardware accelerator can implement a specific AI algorithm, such as matrix multiplication, or a specific AI application, such as speech recognition.
An analogy to Understand Hardware Accelerators
Let’s consider a hardware accelerator in the context of a factory.
Imagine you have a general-purpose worker (analogous to a central processing unit or CPU) in the factory. This worker is skilled and versatile, capable of handling a variety of tasks but may not be exceptionally fast at any particular job. Now, the factory has a specific task that needs to be done repeatedly and requires a specialized skill set.
Here’s where the hardware accelerator comes in – it’s like bringing in a highly specialized expert for that specific task. This expert is incredibly efficient at doing that particular job, much faster than the general-purpose worker. By assigning the specialized expert to handle the repetitive task, the overall productivity of the factory increases.
In this analogy:
- General-Purpose Worker (CPU): Represents the versatile but not necessarily optimized central processing unit (CPU) in a computer. It can handle a wide range of tasks but might not be the most efficient for certain specialized operations.
- Specialized Expert (Hardware Accelerator): Represents the hardware accelerator, designed specifically for certain types of computations. It excels at a particular task and can outperform the general-purpose worker in that specific area.
Why are hardware accelerators needed?
- Efficiency: Hardware accelerators are designed to be highly efficient at specific tasks. They can perform these tasks faster and more energy-efficiently than a general-purpose processor.
- Specialization: Certain applications, like graphics rendering, machine learning, or cryptographic operations, have specific patterns and computations that can be optimized with dedicated hardware. Hardware accelerators are tailored to excel in these areas.
- Performance: When dealing with computationally intensive tasks, a hardware accelerator can significantly enhance overall system performance by offloading specific workloads from the CPU.
- Parallelism: Many hardware accelerators, such as GPUs, are capable of parallel processing, meaning they can handle multiple tasks simultaneously. This parallelism further speeds up certain types of computations.
Types of Hardware Accelerators for AI
Hardware accelerators for AI can be classified into different categories based on their architecture, technology, or target domain. Some of the common types and examples of hardware accelerators for AI are:
Custom-designed chips, known as Application-Specific Integrated Circuits (ASICs), optimize for a specific AI application or algorithm. They can offer the highest performance and efficiency, but they are also the most expensive and inflexible.
Cloud or edge servers typically deploy ASICs to handle large-scale and complex AI workloads. Examples of ASICs for AI include Google’s Tensor Processing Units (TPUs) and Amazon’s Inferentia, both designed for deep learning inference.
Reconfigurable chips, known as field-programmable gate arrays (FPGAs), enable the implementation of various AI algorithms or applications through programmable reconfiguration. They can offer high performance and flexibility, but they are also more complex and power-hungry than ASICs.
Intel’s Arria and Stratix FPGAs stand out as prime examples of FPGA technology deployed in edge devices, adeptly handling diverse and dynamic AI workloads, specifically designed for deep learning inference and training.
Neuromorphic chips are chips that mimic the structure and function of biological neural networks. They can offer low power consumption and high adaptability, but they are also less mature and accurate than ASICs and FPGAs.
Embedded devices often deploy neuromorphic chips to manage low-power and real-time AI workloads. Examples of neuromorphic chips for AI include IBM’s TrueNorth, tailored for cognitive computing, and Intel’s Loihi, optimized for spiking neural networks.
Quantum processors are chips that use quantum mechanical phenomena, such as superposition and entanglement, to perform computation. It can offer exponential speedup and scalability, but they are also very noisy and unstable.
Quantum computers deploy quantum processors to tackle hard and intractable AI problems. Examples of quantum processors for AI include IBM’s Qiskit, specifically designed for quantum machine learning, and Google’s Sycamore, designed to achieve quantum supremacy.
Challenges and Opportunities for Hardware Accelerators for AI
Hardware accelerators for AI are not without challenges and opportunities. Some of the main challenges and opportunities for hardware accelerators for AI are:
-Compatibility and Interoperability: Hardware accelerators for AI need to be compatible and interoperable with existing software frameworks, platforms, and standards. This requires hardware accelerators to support common interfaces, formats, and protocols, such as OpenCL, ONNX, and PCIe and also to provide software tools, such as compilers, libraries, and drivers, to facilitate the development and deployment of AI applications.
-Diversity and Heterogeneity: Hardware accelerators for AI need to cope with the diversity and heterogeneity of AI workloads, algorithms, and applications. This requires hardware accelerators to cooperate and coordinate with other hardware devices, such as CPUs and GPUs to form a heterogeneous computing system.
-Security and Privacy: Hardware accelerators for AI need to ensure the security and privacy of AI data, models, and results. This also requires hardware accelerators to support different mechanisms, such as homomorphic encryption, federated learning, and differential privacy, to enable secure and private AI computation to protect the confidentiality and authenticity of AI information.
Hardware accelerators are devices that can accelerate AI workloads and improve AI performance and efficiency. It can offer significant benefits over general-purpose processors, which are not optimized for AI tasks. Hardware accelerators can be classified into different types, such as ASICs, FPGAs, neuromorphic chips, and quantum processors, based on their architecture, technology, or target domain.
Hardware accelerators also face various challenges and opportunities, such as compatibility, diversity, and security, which require further research and development. In the future of AI, hardware accelerators are poised to play a crucial role by empowering more robust and sustainable AI applications and systems.