Ancient Web: Dan Luu Measured Why a 1977 Computer Could Feel Faster

Part of the Ancient Web Collection.

What if a computer with a one-megahertz processor responds to your typing faster than a laptop with billions of transistors? Dan Luu decided to measure the feeling instead of trusting his memory.

Read Computer Latency: 1977–2017.

Luu carried a high-speed camera around and recorded how long various machines took to display a typed character after a key was pressed. His results were striking. An Apple IIe scored around 30 milliseconds; a Texas Instruments TI-99/4A around 40; a Commodore PET 4016 around 60. A 2014 MacBook Pro and a number of 2016–17 laptops took substantially longer in his tests.

The table includes CPU clock speeds and transistor counts precisely because those modern specifications are so much more impressive than the measured response times. It also compares different operating systems on the same machine, and a custom PC at refresh rates ranging from 24 to 165 hertz.

Speed is a chain, not one number

A screen can only respond after an input device, operating system, application, graphics subsystem, and display have each done their work. Optimizing raw computation does not eliminate every delay added elsewhere. The article also tests browser scrolling on phones and tablets, extending the investigation beyond desktop terminals.

Luu is careful to describe his method. The main figures measure the interval from keypress to visible character, not a machine's overall processing speed. His appendix discusses error sources and variations in the results, which should not be universalized to every example of a particular computer.

The article is a later historical-comparison exception, not a website claiming a 1977 publication date. It matters because it puts a characteristic piece of computing nostalgia to an empirical test and preserves observations of particular older machines in use. It also gives historians a reminder that users experience responsiveness rather than gigahertz.

One of the nicest details is a row for a packet traveling from New York around the world through Tokyo and London. In this comparison, waiting for a sluggish local interface could take roughly as long as sending data across oceans.

Explore the test table and methodology.

Part of the Ancient Web Collection.