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Classic and relevant quote from 1985-ish: "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway."

Today, the equivalent may be an autopilot Tesla Model X full of microSD cards. Terabyte-per-second calculations left as an exercise to the reader.

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Assuming the internal storage volume of the Tesla (which I assume is actually the boots/trunks of the car) is 88.1 cubic feet [https://www.tesla.com/support/model-x-specifications] or 2.49 m^3.

A microSD card is 165 mm^3 = 1.65e-7 m^3.

Dividing one by the other: 15090909 microSD cards could be put in the car [This is simultaneously probably unrealistically high due to the assumed ideal packing and also low due to the large amount of space left in the car].

256GB is the largest microSD card I can actually buy: This is gives us 3.8 exabytes of data hurtling down the highway.

How to efficiently load/unload this data is beyond me. (Short of magic wireless microSD).

V unira'g purpxrq nal bs guvf, V'z n ovg qehax.

A similar calc with LTO-8 tapes comes out at 126PB per Model X. Not as dense, but the advantage is that tape robots and tape libraries go a little way towards automating the load/unload.

A Google search for “88.1 cu ft / 165mm^3 * 256GB” largely confirms your calculation (just over 3.8 XB of data). Can’t say I’m surprised - MicroSD cards really are crazy dense these days.

If it takes an hour to get to your destination (ignoring load/unload time), that’s an aggregate data rate of around 1000 TB (1 PB) per second. The entire Internet averages something like ~25 TB/s, so our Tesla X has the bandwidth of forty Internets.

Of course, there’s a downside: that many MicroSD cards would actually weigh around 3.7 tons (at 250mg apiece), which is heavier than the Model X itself! Might be harder than expected to make the drive itself.

Relevant XKCD (because there always must be one): https://what-if.xkcd.com/31/

I wonder if there have actually been 15M 256GB microSD cards even manufactured at this stage.

Today, the equivalent is an Amazon Snowmobile, a 45 foot shipping container weighing 34 tons transported on a semi-truck. Transfers about 100 petabytes at a time. They claim it can be filled "in less than 10 days". Of course, multiple Snowmobiles can be used in parallel if you have exabytes to transfer.

Assuming it takes about 3 weeks to turn around, my arithmetic says each truck has a bandwidth of about 460 Gbps.

"Q: How do I connect my data center to Snowmobile?

Each Snowmobile comes with a removable high-speed connector rack on wheels with two kilometers of ruggedized networking cable."

Source: https://aws.amazon.com/snowmobile/

Some places straight up mail hard drives back and forth. It can be quicker per GB and/or cheaper depending on what links are available. Also, you generally wont have that bandwidth lost to other users' on the network. The shipping companies are happy to take their money, too. :)

My lab does this. The last step in each experiment is to unplug the hard drive and carry it back to the office for analysis. We have gigabit Ethernet but this is still way faster.