691: MicroSD

Explain xkcd: It's 'cause you're dumb.
Revision as of 13:52, 30 December 2023 by (talk) (Explanation: updated microSD's max capacity)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
That card holds a refrigerator carton's worth of floppy discs, and a soda can full of those cards could hold the entire iTunes store's music library. Mmmm.
Title text: That card holds a refrigerator carton's worth of floppy discs, and a soda can full of those cards could hold the entire iTunes store's music library. Mmmm.


microSD is one format of the Secure Digital memory card format, used in digital cameras, cell phones, and other devices. It is very small, only 15×11×1 mm, but can hold large amounts of data. The US dime in contrast has a diameter of 17.91 mm. When this comic was published in January 2010 the maximum capacity for microSD cards was 16GB. The current maximum capacity is 1.5TB (as of December 2023).

The main character in the comic (on the right) thinks about all the ideas that could be expressed by the data in the microSD card, or in a library. He feels not just reverent and intimidated, but sexually aroused by the thought. As he begins to touch it, his friend is disgusted by what might happen if he uses the card as some kind of sex toy, and does not want to help him locate the card if it gets "lost" inside a body cavity.

The title text seems to be the main character thinking about how much data the card holds, in terms of floppy disks and the iTunes music library, and feeling aroused by these thoughts.

Randall's claims in the title text do check out. A high-density floppy disk with a FAT format holds about 1.4 MB of data, and has dimensions of 90×94×3 mm, for a volume of about 25 cm³. A refrigerator carton is the large cardboard box that fridges are delivered in. A typical refrigerator carton may be 1800×700×700 mm, a volume of about 0.9 m³. So a fridge carton could hold about thirty-five thousand 90 mm floppies, or roughly 50GB. This is comparable to the storage on a single microSD card. A soda can (500 ml = 500 cm³) could hold three thousand microSD cards or store 50TB of data (4500TB today). The iTunes store claimed to hold thirty-five million songs in Summer 2016, and allowing for about 2MB per song gives 70 TB of music. But the library would have been smaller in Spring of 2014 when the comic was created. As of January 2023, Apple Music had about 100 million songs, with much larger average file sizes of around 6 MB. That amounts to about 600 TB total, which is still far less than the 3000 TB that could fit in a soda can of microSD cards at the time. So Randall's claim seems to be correct.

There is a what if blog entry related to this topic.


[Cueball and a friend approach a table.]
Cueball: Hey, what's up?
Friend: Shhhhh.
Cueball: Hrm?
Friend: There's a microSD card on your table.
[A 16GB microSD card sits next to an assortment of coins for size reference.]
Cueball (out of panel): So?
Friend (out of panel): I dunno, high storage densities freak me out. A whole aisle of library shelves on something smaller than a dime.
[The two people stand near the table, the friend peering at the coins and card on the table.]
Friend: Libraries are unnerving enough-millions of ideas surrounding you, towering over you. These cards fill me with that same reverence, that same intimidation.
[Cueball stands alone.]
Friend (out of panel): ...that same faint arousal. Maybe I'll just touch it.
Cueball: If you lose that card I'm NOT helping you find it.

comment.png add a comment! ⋅ comment.png add a topic (use sparingly)! ⋅ Icons-mini-action refresh blue.gif refresh comments!


Please include definition of refrigerator carton. Also, what is the average storage capacity of a floppy disk? 00:08, 19 May 2014 (UTC)

These days refrigerators come in cartons for safe storage. Also you can open them to store floppy discs, which is a lot easier than trying to load them in soda cans. Especially the unopened ones. -- Weatherlawyer (talk) (please sign your comments with ~~~~)
But what is a refrigerator carton? What do you mean they "come in cartons for safe storage"? What's a carton? Is it a cardboard box that fits a whole refrigerator? A wooden crate? A bunch of pillows surrounding the fridge? What is it?
When I do a Google search, I find cardboard boxes with insulating liners designed to hold dry ice, regular ice, or other cold and possibly leaky ingredients, which is not what you said. I think that's what Randall meant. But mostly my searches yield an almost random assortment of cardboard boxes which are coincidentally associated with fridges in some way, which suggests it is a term Randall uses but not one recognized by the general public. Since these are so obscure, the article should probably explain. At a minimum, we need a volume estimate, which we can't really get from the context, since both floppies and SD cards spanned orders of magnitude of storage at the time.EebstertheGreat (talk) 04:01, 26 May 2023 (UTC)

A soda can of then's microSD cards could hold the whole iTunes library then. A soda can of now's microSD cards could hold the whole iTunes library now. I do not see the issue or what seems unreasonable. 02:55, 8 September 2017 (UTC)

Changed “January 2021” to “November 2022” as it has remained that the maximum digital storage size commercially mass produced and available for microSD cards is one terabyte. SilverTheTerribleMathematician (talk) 07:26, 8 December 2022 (UTC)

Excellent —While False (museum | talk | contributions | logs | rights | printable version | page information | what links there | related changes | Google search | current time: 20:58) 07:38, 8 December 2022 (UTC)

Updated to May 2023. As of February, 1.5TB cards have been available. 2TB cards might be available relatively soon, likely in less than 6 months, but we'll see.EebstertheGreat (talk) 04:10, 26 May 2023 (UTC)