The Evolution of Computer Architecture: A Look at the ACM Turing Award Recipients John L. Hennessy and David A. Patterson

Vicki Hanson, the president of ACM, introduced the Turing Award in 1966 to recognize technical contributions. The award was presented at the symposium on computer architecture, where John L. Hennessy and David A. Patterson were honored for their work on energy-efficient RISC-based processors.

John L. Hennessy, former president of Stanford, and David A. Patterson, retired professor from the University of California, Berkeley, revolutionized computer architecture by developing a set of simple and general instructions for reduced instruction set computing (RISC). Their work led to the creation of the RISC one processor in 1982 and influenced microprocessor design for over 25 years.

Hennessy and Patterson's work on RISC-based processors has had a profound impact on the industry. Their book 'Computer Architecture: A Quantitative Approach' has influenced generations of engineers and accelerated advancements in microprocessor design. Today, over 16 billion microprocessors, including those in embedded devices for the internet of things, are based on their principles.

John Hennessy and Dave Patterson presented their work together, highlighting the history of computer architecture and the evolution of domain-specific architectures. They discussed the challenges faced by IBM in the early 1960s and the development of unified instruction sets to handle diverse software stacks and markets.

In the early 1960s, IBM engineers bet the company on developing a unified instruction set to address the challenge of incompatible systems. Maurice Wilkes proposed the idea of using ROM for control logic, leading to the successful implementation of a unified instruction set in April 1964. This innovation revolutionized mainframe computing and set the stage for future advancements.

With the advent of Moore's Law, control stores evolved to become more flexible and efficient. The concept of Writable Control Store emerged, allowing for dynamic changes to microinstructions stored in RAM. This innovation, exemplified by the VAX instruction set with 5000 microinstructions, marked a significant advancement in computer architecture.

Microprogramming allowed for tailoring computer applications, a concept that intrigued the speaker during their graduate studies. Their PhD thesis and first paper were presented at SIGMICRO, an International Workshop known for its contributions to computer architecture.

In 1973, the Alto computer, with writable control, was a groundbreaking innovation. It marked the beginning of microcode usage and introduced capabilities like bit lithographic nomination.

The era saw intense competition among microprocessor manufacturers, with MOS Technology leading the charge. This period was characterized by rapid growth and the introduction of new instructions to outperform competitors.

Under the leadership of Gordon Moore, Intel embarked on an ambitious 32-bit microprocessor project in Oregon. Despite significant advancements, the project faced challenges with chip integration and performance issues.

IBM's decision to use the 8088 processor for their PC, instead of the 68000, proved to be a monumental success. The compatibility with existing software and the market demand led to the sale of over a hundred million units.

The shift towards high-level languages like UNIX marked a significant change in programming paradigms. This transition allowed for the development of complex systems using simpler instructions, leading to improved performance.

Research conducted by Joel Emer revealed that using a microcode interpreter resulted in a 60% increase in instruction set size. This finding prompted a reevaluation of the necessity of complex instructions for optimal performance.

The speaker proposed a novel approach to memory usage by utilizing fast memory as a cache for instructions. This innovative concept aimed to streamline processing and eliminate the need for an interpreter, enhancing overall system efficiency.

During the era discussed, there were significant advancements in chip technology. Chips were becoming more advanced, with the ability to incorporate cache on a single chip. This progress was marked by a breakthrough in register architectures, particularly highlighted by Greg Chaitin's work using graph coloring.

Berkeley played a key role in investigating architecture during that time. Graduate students conducted research on the architecture mentioned earlier, leading to the development of more efficient versions. This work laid the foundation for future advancements in chip technology.

There was a transition from Complex Instruction Set Computing (CISC) to Reduced Instruction Set Computing (RISC). RISC architectures executed fewer instructions but required more clock cycles. This shift in architecture had a significant impact on the industry, with RISC designs dominating the market.

The evolution of chip technology led to the rise of System on Chip (SOC) designs. These designs integrated multiple components onto a single chip, offering increased efficiency and performance. This shift in technology marked a significant departure from traditional chip architectures.

Intel introduced the Explicitly Parallel Instruction Computing (EPIC) architecture as a successor to VLIW. EPIC aimed to enhance performance by utilizing wider instructions, with the compiler handling the workload. This architectural shift represented a move towards 64-bit computing and marked a significant milestone in chip technology.

Despite initial enthusiasm for EPIC architecture, it faced numerous challenges. Issues such as code size, cache misses, and complexity in scheduling instructions posed significant obstacles. The EPIC architecture ultimately failed to deliver on its promises, leading to its eventual decline in the industry.

The speaker discussed the consensus on instruction sets and mentioned the proposal of microcode sets after more than 30 years. VLIW (Very Long Instruction Word) was highlighted as not working for general-purpose use but finding a place in specific applications due to its lack of caches.

The discussion shifted to current challenges in technology, including the end of Dennard scaling and the slowdown in processor performance. The speaker emphasized the need to rethink architectural ideas and address inefficiencies in instruction exploitation.

The evolution of performance was traced from an early 22% annual improvement to a point where dramatic performance gains were achieved before hitting a plateau. The end of Dennard scaling was noted as a significant factor necessitating a reevaluation of technological approaches.

The importance of energy efficiency was highlighted as a key consideration for future technological advancements. The speaker emphasized the need to address power consumption challenges and the inefficiencies in current techniques, such as the diminishing effectiveness of cache.

Security challenges in technology were discussed, drawing parallels to the critical nature of reliable systems in other industries like aviation and automotive. The speaker emphasized the need for robust security measures to prevent malfunctions and ensure system reliability.

The speaker referenced historical architectural techniques from the 1970s, such as domains and rings, that were piloted but did not achieve expected performance improvements. Issues with translation techniques and virtual memory were highlighted, showcasing the challenges faced in implementing high-performance solutions.

The challenges of software verification were discussed, noting the prevalence of bugs in software despite efforts to implement formal verification processes. The speaker highlighted the historical rise of kernel sizes in operating systems and the persistent issue of software bugs in modern systems.

The speaker discusses the security challenges in hardware architecture, highlighting the issue of Intel processors running code before any kernel operating system. He mentions the presence of numerous vulnerabilities that have gone unnoticed for years, emphasizing the need for a reevaluation of security measures in light of evolving threats.

The speaker reflects on the implications of the slowdown in Moore's Law on security, describing it as a 'tragedy' due to the messy state of architectural security. He emphasizes the necessity to redefine approaches to security in the face of emerging challenges and increasing timing attacks.

The speaker explores opportunities in software development amidst technological shifts, quoting Maurice Wilkes on the potential impact of Moore's Law slowdown. He advocates for a shift towards hardware-centric approaches and specialized processors to enhance software performance and execution efficiency.

The speaker delves into the importance of optimizing software performance, citing a study by Leiserson and a group that achieved a 47x speed improvement through software optimization techniques. He emphasizes the significance of leveraging parallelism, cache optimization, and specialized instructions to enhance software efficiency.

The speaker discusses the concept of domain-specific architectures tailored to specific applications, such as neural networks and programmable network switches. He advocates for programmable machines that cater to diverse application requirements, highlighting the effectiveness of specialized architectures in improving performance and flexibility.

The speaker addresses the challenges in efficiently extracting knowledge to hardware, noting the complexity of the problem. He highlights the difficulty faced by compiler experts in optimizing hardware efficiency, emphasizing the need for innovative solutions to tackle the inherent complexities.

The discussion highlights the necessity for higher-level language vectors or other specified operations to ensure independence in mapping to different architectures.

There is a mention of making Python programs run like C to achieve significant performance improvements, with the speaker suggesting that achieving this feat would make one a hero.

The conversation shifts towards the growing interest in machine learning applications, emphasizing the potential for significant advancements in this field.

The importance of optimizing memory access in architectures is discussed, with a focus on building memory systems tailored to specific tasks like matrix multiplication.

There is a call for a renaissance in computer architecture, advocating for a shift towards interdisciplinary teams that combine expertise in languages, compilers, and underlying technologies to drive innovation.

The speaker advocates for a return to vertically integrated systems, highlighting the benefits it can provide to both academic and commercial computer architecture endeavors.

The discussion delves into the development of the RISC-V instruction set, initiated by Krste Asanović and his team to create a clean slate instruction set architecture, leading to significant advancements in chip design.

RISC-V is a new instruction set architecture that stands out due to its simplicity. Unlike x86, which has a manual of about 200 pages, RISC-V is designed to be clean and modular, with a standard base that everyone must have and optional extensions for customization. The design aims to avoid past mistakes and offers a significant opcode space for domain-specific instructions.

RISC-V's design is community-driven, with a base of standard extensions that can be expanded with additional features. Unlike traditional architectures, where software support follows hardware announcements, RISC-V involves software developers in the design process upfront. This approach ensures compatibility and fosters innovation.

Several industry players have embraced RISC-V, with companies like nVIDIA, Western Digital, and Changhong announcing products based on the architecture. These announcements indicate a growing trend towards using RISC-V in various applications, from microcontrollers to consumer electronics, highlighting the architecture's versatility and appeal.

RISC-V's open nature extends beyond just the instruction set to include implementations and standards. This openness appeals to companies and countries concerned about security, as it allows for transparency and collaboration in addressing potential vulnerabilities. The architecture's flexibility also enables novel designs and rapid iteration, making it an attractive option for security-focused applications.

RISC-V's simplicity and lack of marketing constraints make it an appealing choice for a wide range of applications. The architecture's ease of implementation and customization can cater to both low-end and high-end requirements without compromising performance or scalability. This adaptability positions RISC-V as a competitive option in the processor market.

The future outlook for RISC-V is optimistic, with a focus on global adoption and domination. The architecture's open and versatile nature, coupled with its potential for security applications, positions it as a leading contender in the processor market. The goal of achieving world domination reflects the ambition and confidence in RISC-V's capabilities.

Around 15 years ago, there was a rebellion against the Waterfall model of software development, advocating for short development cycles, working prototypes, and rapid iterations.

The Agile development model, inspired by rugby team dynamics, focuses on iterative development where teams build, test, and adapt software in short cycles.

Modern software development allows small teams to utilize Agile methodologies, enabling rapid prototyping and iterative improvements.

Software design involves reusing lines of code across different designs, with minimal unique code, leading to efficient development processes.

Hardware design can leverage Field-Programmable Gate Arrays (FPGAs) for quick prototyping and testing, with the added benefit of cloud-based FPGA instances for cost-effective development.

Hardware development involves physical prototyping to test functionality, power consumption, and performance, providing a tangible outcome for evaluation.

Advancements in technology have made test chips with RISC-V cores and nVIDIA DLA accessible at a cost of $14,000, enabling widespread adoption and experimentation.

Adopting an agile model in hardware development, similar to software, allows for quicker iterations, testing, and refinement, leading to superior outcomes.

Innovation in hardware design will likely stem from architects focusing on areas like security, domain-specific languages, and open architectures to create more secure and efficient systems.

Cloud-based FPGAs simplify hardware development by providing easy access to customizable hardware resources, fostering collaboration among developers and accelerating innovation.

According to the speaker, agile development allows everyone to afford making chips, reflecting a positive shift in the industry. The speaker reminisces about the 1980s when they were young architects, highlighting the current great opportunities for architects in academia and industry.

The speaker mentions the speedup from scripting languages and emphasizes the efficiency of a system with millions of lines of code. They acknowledge the complexity of systems with multiple layers of compilers and garbage collection, stating that there is no easy solution.

The speaker discusses the challenges in research, highlighting the need to adapt to changing technologies. They mention the importance of considering the academic community's past struggles with design tools and emphasize the need for innovation and adaptation in the face of evolving technologies.

The speaker reflects on the impact of innovation on grad students, suggesting that adopting new technologies could have prevented stagnation in their academic progress. They emphasize the importance of embracing innovation to drive progress in research and academia.

A student from Duke University discusses domain-specific computing, focusing on approaches to accelerate computing tasks. They highlight the importance of finding efficient solutions directly from hardware architecture, showcasing the potential for innovation in specialized computing domains.

Jason Mars from Michigan discusses the trend towards specialization in hardware design, emphasizing the need to integrate hardware and software solutions. He advocates for a holistic approach to problem-solving, where hardware and software are considered together to drive innovation and progress in the field.

The speaker discusses the evolution of hardware technology, mentioning that modern devices contain more than just a CPU and GPU. Companies have been working on this technology for over a decade, transitioning from CPU and GPU to more specialized components that are energy-efficient and domain-specific.

The speaker talks about a project at Google called Virtual Core, which focused on developing domain-specific hardware. The goal was to create specialized components that are energy-efficient and tied to specific domains, emphasizing the importance of domain-specific solutions in hardware development.

The discussion shifts to addressing gaps in computer science education, particularly in the area of security. The speakers emphasize the need to teach students about security, parallelism, algorithms, and computation, highlighting the importance of preparing graduates for the evolving field of computer science.

The conversation touches on the importance of collaboration between hardware and software disciplines. While the integration of hardware and software is common, there is a cultural gap where software experts may not fully understand the needs of computer science departments. The speakers discuss strategies to bridge this gap and enhance collaboration between the two domains.

Looking ahead, the speakers emphasize the need for architects to explain the evolving landscape of hardware technology. They stress that single cores are not getting faster, and the future lies in specialized, energy-efficient components. The discussion highlights the importance of adapting to new technologies and educating others about the advantages of these advancements.

The conversation acknowledges a renaissance in hardware development, with companies building specialized components that require significant resources. While some projects involve tens of millions of dollars, there is a notable absence of emphasis on certain aspects of hardware technology, indicating a shift towards more specialized and resource-intensive projects in the industry.

The speaker discusses the evolution of RISC ISA, highlighting the transition from simple RISC ISA to distributed machines. They mention the challenge of feeding the pipe with data and express the view that it presents an opportunity for innovation.

The conversation shifts to the limitations of compiler technology, specifically in the context of compiling languages like C. The speaker notes that despite efforts to push the technology further, there were constraints when dealing with large applications and reorganizing memory for improved performance.

There is an opportunity for reengagement and renovation in the field of architecture and memory organization. The speaker expresses excitement about the potential for collaboration between software and hardware to drive advancements in performance.

The discussion touches on XLA, a technology focused on high-level compilation. The speaker emphasizes that this approach represents a different perspective and highlights the potential for exploring new methods in the field.

The conversation delves into the future of architecture, with a reference to the Golden Age of architecture. The speakers express optimism about the possibilities for developing domain-specific architectures and fostering innovation within the community.

The integration of machine learning principles in architecture is discussed as a revolutionary approach. The speakers contemplate the implications of using machine learning to design machines better for specific tasks, highlighting the potential for transformative advancements.

The conversation emphasizes the existence of significant opportunities in programming and hardware development. The speakers discuss the need for innovative approaches in programming and highlight the potential for new advancements in the field.

The speakers acknowledge the challenges in research and express the view that existing ideas have been exhausted. However, they also highlight the vast opportunities for innovation and the need to explore new avenues in architecture research.

There is a call for action in architecture research to embrace new challenges and opportunities. The speakers emphasize the importance of crystal clear vision and the need for researchers to drive societal advancements through innovative approaches.