Organizing My Hard Drive

Windows used to (and maybe still does) have a limit on the number of files that can be in the root directly. Beyond that, I'm not sure there's any specific limit to the number of files in a folder / directory.

More to the point, if I understand howardm corrextly, he's suggesting adding a month breakdown between year and y-m-d. That isn't going to change the number of files in a single folder anyway.

If I've got x number of folders named yy-mm-dd, and each folder has 5,000 images in it, that's still true whether the higher level structure is year / day (yyyy/yy-mm-dd) or year / mon / day (yyyy/yy-mon/yy-mm-dd).

The bottom of the file structure is the same, with 5,000 images per folder, and the top actually has more sub-folders with the extra level in the middle.