John McCalpin

AUGUST 1, 2018

According to Dr. Bandwidth, performance analysis has two recurring themes: How fast should this code (or “simple” variations on this code) run on this hardware? The user environment defines the mapping of MPI ranks to hardware resources (cores, sockets, nodes). The MPI runtime library. in ways that are seldom transparent.

Hardware 40

Hardware Transportation Performance Latency 40

Smashing Magazine

JANUARY 11, 2021

Build Optimizations JavaScript modules, module/nomodule pattern, tree-shaking, code-splitting, scope-hoisting, Webpack, differential serving, web worker, WebAssembly, JavaScript bundles, React, SPA, partial hydration, import on interaction, 3rd-parties, cache. Moto G4) on a slow 3G network, emulated at 400ms RTT and 400kbps transfer speed.

Performance 145

Performance Cache Media Metrics 145

Smashing Magazine

JANUARY 6, 2020

If you don’t have a device at hand, emulate mobile experience on desktop by testing on a throttled 3G network (e.g. To make the performance impact more visible, you could even introduce 2G Tuesdays or set up a throttled 3G/4G network in your office for faster testing. 300ms RTT, 1.6 Mbps down, 0.8

Performance 145

Performance Cache Network Metrics 145

Smashing Magazine

JANUARY 7, 2019

If you don’t have a device at hand, emulate mobile experience on desktop by testing on a throttled network (e.g. To make the performance impact more visible, you could even introduce 2G Tuesdays or set up a throttled 3G network in your office for faster testing. 150ms RTT, 1.5 Mbps down, 0.7 Mbps up) with a throttled CPU (5× slowdown).

Performance 103

Performance Cache Metrics Network 103

Alex Russell

OCTOBER 22, 2017

We constrain ourselves to a real-world baseline device + network configuration to measure progress. Budgets are scaled to a benchmark network & device. JavaScript is the single most expensive part of any page in ways that are a function of both network capacity and device speed. The median user is on a slow network.

Performance 68

Performance Benchmarking Network Mobile 68

Smashing Magazine

AUGUST 22, 2021

As we will see, QUIC and HTTP/3 indeed have great web performance potential, but mainly for users on slow networks. If your average visitor is on a fast cabled or cellular network, they probably won’t benefit from the new protocols all that much. An often used metaphor is that of a pipe used to transport water. Did You Know?

Performance 105

Performance Network Latency Servers 105