What is the actual maximum supported size for microSD cards on A64 boards?

[mossroy]

According to the specs from https://www.olimex.com/Products/OLinuXino/A64/A64-OLinuXino/open-source-hardware , the microSD card connector supports "cards up to 32GB"

But I tested a 64GB microSD card on a A64-OLinuXino-2Ge8G-IND, and it seems to work (at least with Armbian_20.02.7_Lime-a64_buster_current_5.4.28 image on it).
Only 58GB are detected by fdisk, and 55GB are available on the ext4 filesystem, but maybe it's normal.
It's a Kingston SDC10G2/64GB.

What is the actual maximum microSD card we can use on these boards? Would a 128GB card (or more) be supported?

[mossroy]

It also works on a 128GB microSD card (tested on a Kingston Canvas Select Plus SDCS2/128GB, with the same image as above). 114GB are available on the ext4 filesystem.

I don't understand why the official spec mentions a 32GB limit

[LubOlimex]

I don't understand either so I removed that part.

There is no size limitation but there is speed recommendation. It is recommended to get A1 or slower card since A2 or faster cards might lack proper software support in Linux. Of course, don't get the slowest card possible since that would affect performance.