Chips and Cheese investigated Zen 5's AVX-512 behavior and found that while AVX-512 is enabled and functional, using these instructions significantly reduces clock speeds. Their testing shows a consistent frequency drop across various AVX-512 workloads, with performance ultimately worse than using AVX2 despite the higher theoretical throughput of AVX-512. This suggests that AMD likely enabled AVX-512 for compatibility rather than performance, and users shouldn't expect a performance uplift from applications leveraging these instructions on Zen 5. The power consumption also significantly increases with AVX-512 workloads, exceeding even AMD's own TDP specifications.
"Anatomy of Oscillation" explores the ubiquitous nature of oscillations in various systems, from physics and engineering to biology and economics. The post argues that these seemingly disparate phenomena share a common underlying structure: a feedback loop where a system's output influences its own input, leading to cyclical behavior. It uses the example of a simple harmonic oscillator (a mass on a spring) to illustrate the core principles of oscillation, including the concepts of equilibrium, displacement, restoring force, and inertia. The author suggests that understanding these basic principles can help us better understand and predict oscillations in more complex systems, ultimately offering a framework for recognizing recurring patterns in seemingly chaotic processes.
Hacker News users discussed the idea of "oscillation" presented in the linked Substack article, primarily focusing on its application in various fields. Some commenters questioned the novelty of the concept, arguing that it simply describes well-known feedback loops. Others found the framing helpful, highlighting its relevance to software development processes, personal productivity, and even biological systems. A few users expressed skepticism about the practical value of the framework, while others offered specific examples of oscillation in their own work, such as product development cycles and the balance between exploration and exploitation in learning. The discussion also touched upon the optimal frequency of oscillations and the importance of recognizing and managing them for improved outcomes.
Summary of Comments ( 45 )
https://news.ycombinator.com/item?id=43215781
Hacker News users discussed the potential implications of the observed AVX-512 frequency behavior on Zen 5. Some questioned the benchmarks, suggesting they might not represent real-world workloads and pointed out the importance of considering power consumption alongside frequency. Others discussed the potential benefits of AVX-512 despite the frequency drop, especially for specific workloads. A few comments highlighted the complexity of modern CPU design and the trade-offs involved in balancing performance, power efficiency, and heat management. The practicality of disabling AVX-512 for higher clock speeds was also debated, with users considering the potential performance hit from switching instruction sets. Several users expressed interest in further benchmarks and a more in-depth understanding of the underlying architectural reasons for the observed behavior.
The Hacker News post titled "Zen 5's AVX-512 Frequency Behavior," linking to a Chips and Cheese article, has generated a moderate number of comments, primarily discussing the technical details and implications of the article's findings.
Several commenters focus on the performance trade-offs observed with AVX-512 on Zen 5. Some highlight the significant frequency drops when using AVX-512 instructions, questioning the practical benefit given the reduced clock speeds. One commenter points out the potential for increased power consumption despite the lower frequency due to the higher voltage required for AVX-512. Others discuss the impact on overall system performance, noting that even if AVX-512 provides theoretical advantages, the frequency reduction could negate these gains in real-world applications.
The discussion also touches on the complexities of power management in modern CPUs. Commenters explain how different instruction sets place varying demands on the power delivery system, leading to dynamic frequency adjustments. One comment suggests that the observed behavior might be due to power limits being reached, rather than an inherent limitation of the Zen 5 architecture. Another commenter speculates about the potential for future optimizations, suggesting that BIOS updates or software tweaks could mitigate the frequency drops.
A few comments delve into the technical details of AVX-512 implementation, discussing topics like vector units and instruction throughput. One commenter questions the efficiency of using AVX-512 for certain workloads, given the observed performance characteristics. Another commenter mentions the challenges of software utilizing AVX-512 effectively and the importance of compiler optimization.
Some comments compare Zen 5's AVX-512 behavior to other architectures, including Intel's offerings. One commenter suggests that while Zen 5 may face frequency reductions, it still offers competitive performance in AVX-512 workloads compared to some Intel CPUs.
Overall, the comments section provides valuable insights into the technical nuances and practical implications of AVX-512 on Zen 5. The discussion highlights the complex interplay between instruction sets, frequency scaling, and power management in modern CPUs. While some comments express concerns about the observed performance trade-offs, others offer potential explanations and suggest avenues for future optimization. The discussion remains focused on the technical aspects raised by the linked article, without delving into broader market analysis or speculation.