[hermitcrab]

CSV is a questionable choice for a dataset that size. It's not very efficient in terms of size (real numbers take more bytes to store as text than as binary), it's not the fastest to parse (due to escaping) and a single delimiter or escape out of place corrupts everything afterwards. That not to mention all the issues around encoding, different delimiters etc.

[zzbn00]

Its great for when people need to be in the loop, looking at the data, maybe loading in Excel etc. (I use it myself...). But not enough humans around for 21 GB/s

[jstimpfle]

> (real numbers take more bytes to store as text than as binary)

Depends on the distribution of numbeds in the sataset. It's quite common to have small numbers. For these text is a more efficient representation compared to binary, especially compared to 64-bit or larger binary encodings.