Modern Computer Architecture & Organization • Jim Ledin & Maciej «MJ» Jedrzejewski • GOTO 2026

This interview was recorded for the GOTO Book Club. #GOTOcon #GOTObookclub http://gotopia.tech/bookclub Check out more here: https://gotopia.tech/articles/452 Jim Ledin - President at Ledin Engineering & Author of “Modern Computer Architecture and Organization” @jledin1 Maciej «MJ» Jedrzejewski - Tech Agnostic Architect & Author of “Master Software Architecture” @learnsoftwarearchitecture RESOURCES Jim https://www.linkedin.com/in/jimledin https://x.com/ledin_eng https://github.com/jledin https://ledin.com MJ https://github.com/meaboutsoftware https://www.linkedin.com/in/jedrzejewski-maciej https://www.fractionalarchitect.io Links https://youtu.be/wNT2qkusVrA https://youtu.be/Pv0cfsastFs https://youtu.be/cI9dfQLTXlU https://youtu.be/a2DvXnecXVk DESCRIPTION Jim Ledin — author of Modern Computer Architecture and Organization, now in its third edition — joins Maciej "MJ" Jedrzejewski to talk through the book's two brand-new chapters on GPUs and large language models, and the specific challenge of writing about hardware that changes faster than a book can ship. Ledin's approach was to focus on durable architectural principles (parallelism, memory bandwidth, tensor processing, and how systems scale from one chip to an entire data center rack) rather than chasing the current state of the art. For the LLM chapter specifically, he chose GPT-2 as the teaching example precisely because it's open-source and small enough to trace by hand — and because, as he explains, the transformer architecture underneath today's frontier models is fundamentally the same structure, just scaled up. The most concrete takeaway for engineers: the AI buildout's real bottleneck right now isn't compute, it's memory bandwidth — a shift driving high-bandwidth memory production at the expense of consumer RAM, which Ledin illustrates with a blunt data point (a 32GB DDR5 stick that cost $69 a year ago now runs $440). But asked which single chapter would most change how a working developer with no hardware background thinks about their own code, Ledin doesn't point to AI at all — he points to the chapter on pipelining and cache hierarchy, arguing that most of the thousandfold speedup from 1980s PCs to today came from those optimizations, not clock speed, and that writing cache- and pipeline-friendly code is still one of the highest-leverage skills a developer can have. TIMECODES 00:00 Intro 00:47 The Commodore 64 that started it all 04:36 Two new chapters: GPUs & LLMs 10:00 Why GPUs became AI hardware by accident 13:33 Training vs Inference: Same chip, different job 15:03 Why GPT-2, not GPT-5, is the best teacher 17:37 The data center is the computer now 18:41 The real AI bottleneck nobody's talking about 21:59 The one chapter every developer should read 25:43 Outro RECOMMENDED BOOKS Jim Ledin • Modern Computer Architecture and Organization • https://amzn.to/4wHMhQN Jim Ledin • Architecting High-Performance Embedded Systems • https://amzn.to/3UpXl7z Jim Ledin • Simulation Engineering • https://amzn.to/4qvylYQ Maciej «MJ» Jedrzejewski • Master Software Architecture • https://leanpub.com/master-software-architecture https://bsky.app/profile/gotocon.com https://twitter.com/GOTOcon https://www.linkedin.com/company/goto- https://www.instagram.com/goto_con https://www.facebook.com/GOTOConferences #ComputerArchitecture #ComputerOrganization #ModernComputerArchitectures #Hardware #HardwareFoundations #GPU #Microchips #AIDatacenters #SoftwareEngineering #TodayInTech #Programming #JimLedin #MaciejJedrzejewski #GOTO #BookClub CHANNEL MEMBERSHIP BONUS Join this channel to get early access to videos & other perks: https://www.youtube.com/channel/UCs_tLP3AiwYKwdUHpltJPuA/join Looking for a unique learning experience? Attend the next GOTO conference near you! Get your ticket at https://gotopia.tech Sign up for updates and specials at https://gotopia.tech/newsletter SUBSCRIBE TO OUR CHANNEL - new videos posted almost daily. https://www.youtube.com/user/GotoConferences/?sub_confirmation=1