efficiency

Bjorn Nyland compares wireless and wired DC fast charging for an electric car, measuring end-to-end efficiency. The test shows the wireless system holding up well against a plug.

Chandler Carruth's CppCon 2014 talk on writing fast C++, explaining why data structure choice and memory layout matter more than clever algorithms. It covers why standard containers like unordered_map perform poorly on modern CPUs.

Dave Ackley gives a high-level introduction to robust-first computing, which prioritizes robustness over efficiency in computer architecture. A sorting demo illustrates the idea.

Minutephysics compares how efficiently different processes convert mass to energy per E=mc^2, from fire and fission to fusion, antimatter and black holes, which can convert a large fraction of mass to energy.

Practical Engineering explains how canal locks work, including the water-saving basins of the new Panama Canal locks.

Real Engineering examines the efficiency of hydrogen as an energy carrier. It follows production, storage and fuel cell conversion losses and compares hydrogen cars with battery electric vehicles.

Technology Connections explains how refrigerator and freezer design affects energy use, using chest freezers to show why top-opening designs and layout choices matter. It includes thermal-camera footage of cold air spilling out of upright units.

Geekerwan reviews smartphone CPUs by power efficiency rather than benchmark scores, with test methodology and chapters on Qualcomm, Apple, Samsung and Google chips. It explains why high benchmark scores can coexist with heat and poor battery life.

Technology Connections explains why heat pumps matter right now, covering their efficiency, how they hold up in cold weather and the energy savings over burning fuel. It follows his earlier explainer on how they work.

A Technology Connections video on how ground-source (geothermal) heat pumps work and why they hold efficiency in winter. It also covers related heat pump information, and the description notes air-source heat pumps have since improved.

Engineering Explained examines Toyota's hydrogen-burning V8 engine built with Yamaha and explains the practical problems of hydrogen combustion vehicles. It covers efficiency, storage and distribution issues.

Dr. Bruce Bugbee walks through the calculations for crop yield potential when light is the limiting factor, from photosynthetic quantum yield through respiration efficiency and harvest index, using the Energy Cascade Model.

Matt Risinger demonstrates a blower door test on a house, using a fan to measure air leakage and find where air gets in and out. It shows how the test reveals the quality of the build.

Technology Connections explains how heat pumps work as reversed air conditioners and why they can deliver several times the heat of resistive heating per unit of energy. It also tackles common myths such as poor cold-weather performance.

Matt Kulukundis explains how Google designed SwissTable, a fast, cache-friendly hash table, step by step from std::unordered_map. The talk covers open addressing, SIMD probing and the tradeoffs of changing a fundamental data structure.

Technology Connections' long closing video in his heat pump series, arguing that adopting heat pumps is well within reach. It explains how they work and what it takes to start using them.

Technology Connections explains why electric kettles are uncommon in the US, centering on 120V circuits limiting power. He tests ways of boiling water on gas, electric ranges and kettles.

Andrew Kelley, creator of Zig, presents practical data-oriented design techniques for shrinking memory footprint and making programs cache friendly. He ends with a case study of how these ideas sped up the Zig compiler.

Technology Connections explains why single-hose portable air conditioners are inefficient and often a poor choice compared with window units. It details how the single hose pulls in warm outside air and wastes energy.

Technology Connections explains in 33 minutes why thermoelectric (Peltier) cooling is far less efficient than compressor-based refrigeration.

Technology Connections looks at why awnings disappeared from houses and how effective they are at cutting solar heat gain and cooling costs. It argues they are a simple, forgotten cooling technology.

Technology Connections tests how quickly gas, induction and standard electric stoves boil water, with CO2 measurements and a discussion of the advantages and disadvantages of each.

Technology Connections examines why light bulbs have the lifespans they do, including the real history of the Phoebus cartel. He shows that bulb life trades off against brightness and efficiency rather than being simple planned obsolescence.

A Stanford EE380 seminar by Michael P. Frank of Sandia National Laboratories on generalized reversible computing. It surveys unconventional computing approaches as transistor scaling nears its limits and energy efficiency stops improving.

Geekerwan's Chinese-language review of Intel's Lunar Lake lightweight laptop chip, covering performance, perf-per-watt curves and battery life benchmarks. It tests whether x86 can compete on efficiency.

Kirsten Dirksen profiles Steve Rees, who buried two shipping containers to build an earth-cooled, off-grid 640 sq ft home in Northern California for about $30,000, solar included.

Sabine Hossenfelder explains why hydrogen is a poor answer for decarbonization, covering how most hydrogen comes from fossil fuels, the efficiency losses of green hydrogen and reliance on rare metals in fuel cells.

A Technology Connections video weighing LED streetlights against high pressure sodium lamps, covering efficiency, color, cost and light pollution. It is a follow-up to his earlier explanation of why street lights are orange.

Real Engineering explains why biofuels, especially corn ethanol, are a poor energy source, looking at energy inputs, efficiency and carbon cost.

Vim creator Bram Moolenaar's 2007 Google Tech Talk on habits for efficient text editing. He explains how to spot repetition and inefficiency, then use editor features to fix it.

Wendover Productions explains why modern airliners fly no faster than they did decades ago, covering the economics of speed and fuel efficiency, and why supersonic travel faded.

Bill Dally of NVIDIA gives a University of Washington lecture on trends in deep learning hardware. It covers numeric formats, specialized instructions, energy per operation and co-design of hardware and software.

A Margin Call clip in which Will Emerson tries to persuade Eric Dale to return to the firm, and Dale recounts calculating the lifetimes saved by a bridge he helped build.

Armin Ronacher, creator of Flask, explains how CPython's internals and C API leak into the language's semantics. Using examples like the complexity of the add operation, he shows why Python is hard to optimize or reimplement.

Andrei Alexandrescu's CppCon 2015 talk argues that std::allocator is badly designed. He proposes building high-performance allocators from small composable, templated pieces.

The first episode of James Burke's 1978 BBC series Connections traces modern dependence on complex technological networks, starting with the 1965 New York blackout, and moves through ancient agriculture to Kuwait's oil-driven leap.

A DevGAMM talk by Jonathan Blow arguing that civilizations can lose technological capability and that software quality is already deteriorating. He discusses how knowledge fails to transfer between generations.

Emery Berger explains why performance is hard to measure and deliver on modern hardware, showing how code layout and alignment can swamp optimization effects. He presents Stabilizer for statistically sound evaluation and Coz, a causal profiler.

Casey Muratori's long talk arguing that modern software has ballooned to tens of millions of lines because of hardware and OS diversity. He proposes a stable ISA for entire system-on-a-chip packages and recalls when games shipped with their own boot disk.

Rick Reed of WhatsApp explains at Erlang Factory 2014 how the service scaled to billions of messages with a very small engineering team. He covers the FreeBSD and Erlang stack, Mnesia usage, server counts and bottleneck work.