fastimport

fastimport.unpackLimit
If the number of objects imported by linkgit:git-fast-import[1] is below this limit, then the objects will be unpacked into loose object files. However, if the number of imported objects equals or exceeds this limit, then the pack will be stored as a pack. Storing the pack from a fast-import can make the import operation complete faster, especially on slow filesystems. If not set, the value of transfer.unpackLimit is used instead.