gwax's rumblings

Having recently used Virgin America to trans­port myself across the coun­try, I was very pleased to have Internet access while I was in the air. This, how­ever, is not the sort of air­plane band­width and latency that I am going to talk about. Instead, I would like to dis­cuss a com­par­i­son between the band­width and latency of typ­i­cal Internet con­nec­tions with those asso­ci­ated with tak­ing a hard drive on an airplane.

Let’s say we com­pare a high speed (15Mbit) DSL con­nec­tion to tak­ing a mod­er­ately large hard drive (500GB) on a plane for data rates between San Francisco and Boston (~7 hours):

Bandwidth:
DSL: 15 Mbit/s
Airplane: 150 Mbit/s

Latency:
DSL: ~100ms
Airplane: >7 hours

For fun, let’s try some­thing a lit­tle big­ger on both sides: OC-768 vs Boeing 747-400F plane filled with 2TB hard drives.

Bandwidth:
OC-768: 38 Gbit/s
747-400F: 93 Tbit/s

Latency:
OC-768: <100ms
747-400F: >7 hours

Clearly, hard dri­ves on an air­plane will win in a purely band­width dri­ven appli­ca­tion but air­planes suf­fer from incred­i­bly high latency. You will have to decide which is best choice based on your par­tic­u­lar use scenario.