# The truth about tomorrow

Tomorrow has not been yesterday yet for quite some time to be.

Tomorrow has not been yesterday yet for quite some time to be.

How much snark should a snark shark snark if a snark shark should snark snark?

A snark shark should snark as much snark as a snark shark can snark, if a snark shark should snark snark.

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 (\(15\mathrm{Mbit}\)) DSL connection to taking a moderately large hard drive (\(500\mathrm{GB}\)) on a plane for data rates between San Francisco and Boston (\(\approx 7\mathrm{hr}\)):

Bandwidth:

DSL: \(15\frac{\mathrm{Mbit}}{\mathrm{s}}\)

Airplane: \(\frac{500\mathrm{GB}}{7\mathrm{hr}} \times \frac{1\mathrm{hr}}{60\mathrm{min}} \times \frac{1\mathrm{min}}{60\mathrm{s}} \times \frac{8000\mathrm{Mbit}}{1\mathrm{GB}} \approx 150\frac{\mathrm{Mbit}}{\mathrm{s}}\)

Latency:

DSL: \(\approx 100\mathrm{ms}\)

Airplane: \(>7\mathrm{hr}\)

For fun, let's try something a little bigger on both sides: OC-768 vs Boeing 747-400F plane filled with \(2\mathrm{TB}\) hard drives.

Bandwidth:

OC-768: \(38\frac{\mathrm{Gbit}}{\mathrm{s}}\)

747-400F: \(\frac{250000\mathrm{lb}}{7\mathrm{hr}} \times \frac{2\mathrm{TB}}{1.7\mathrm{lb}} \times \frac{1\mathrm{hr}}{60\mathrm{min}} \times \frac{1\mathrm{min}}{60\mathrm{s}} \times \frac{8\mathrm{Tbit}}{1\mathrm{TB}} \approx 93\frac{\mathrm{Tbit}}{\mathrm{s}}\)

Latency:

OC-768: \(<100\mathrm{ms}\)

747-400F: \(>7\mathrm{hr}\)

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.