The Volatile Nature of Download Time Estimates
Description
This image uses the six-panel 'Gru's Plan' meme format to satirize the notorious unreliability of time estimates for downloads or other long-running processes. The text at the top reads, 'When you're downloading something and it gives you a time estimate'. The subsequent panels show the character Gru pointing to a whiteboard with a wildly fluctuating sequence of time estimates: '2 minutes', '30 seconds', '6 hours', '200 years' (this panel shows Gru with glowing red eyes for emphasis), '5 seconds', and finally, 'done.'. The humor is rooted in the shared, frustrating experience of watching a progress bar give nonsensical and unpredictable completion times. This is a common issue in software, caused by factors like network speed variations, disk I/O, and poor estimation algorithms, making it highly relatable to anyone who has ever downloaded a large file, installed software, or run a lengthy build process
Comments
12Comment deleted
Our progress bar is based on the idea of eventual consistency. The time estimate and the actual completion time will eventually be consistent, right at the moment it finishes
Our progress bar ETA must share a codebase with our release planner: optimistic TCP slow-start, a few congestion collapses, a projection that lasts longer than IPv4, and then - miraculously - “done” the second the VP opens Zoom
After 20 years in tech, I've learned that download time estimates follow the same mathematical model as project estimates: take the initial value, multiply by π, add the number of dependencies, then realize it's all quantum superposition anyway - simultaneously done and infinitely far away until you actually observe it
Ah yes, the download time estimate algorithm: take the current transfer rate, multiply by remaining bytes, add a random number generator seeded with user anxiety levels, and update every 100ms with complete disregard for previous predictions. It's like watching a junior dev's first attempt at implementing exponential moving averages - except the junior dev would eventually converge to accuracy, while download ETAs seem to have discovered a novel form of computational chaos theory where the only constant is user suffering
Download ETAs are Bayesian fibs: one packet loss updates the posterior to “200 years,” then a CDN cache hit collapses it to “done.”
Download ETAs are just EWMA fanfic for a non‑stationary channel - slow start, Wi‑Fi jitter, CDN hop… 2 minutes → 200 years → done, the story points of networking
Download ETAs: the only progress bars proving time dilation is real outside relativity - npm install on spotty WiFi
Sometimes it looks like a certain function just returns a random value of time until the download is done Comment deleted
it's because it just does current download speed * size of file - elapsed time rather than average download speed so far * file size left Comment deleted
why the hell would you do (current speed * filesize) - elapsed time? you can very easily end up in negative numbers. you probably meant remaining size / current speed Comment deleted
Usually you average it for like 2-3 seconds so that it doesn’t jump faster than you can read it Comment deleted
among us download task be like Comment deleted