QGIS memory error

[acrosome]

I am trying to use QGIS 3.16 to Merge a bunch of GMTED raster images. I am getting this error:

ERROR 3: /tmp/processing_ROvHme/efc498e9f46047289ac5454ea621f03b/OUTPUT.tif: Free disk space available is 6708756480 bytes, whereas 13824000000 are at least necessary. You can disable this check by defining the CHECK_DISK_FREE_SPACE configuration option to FALSE.

Frustratingly, the Merge function does not appear to have a CHECK_DISK_FREE_SPACE parameter at all! The Help button and the manual list all sorts of neat parameters that you can monkey with, but not that one.
So, I googled around and found this:

https://www.luisalucchese.com/post/g...no-free-space/

Which makes me think that I may be having a similar issue, since as in the example my images should not be taking up anywhere near the amount of space listed in the error. But I don't understand the fix that is presented. Any help would be appreciated.