The missing screw hole is the middle one which is needed for the bracket

runs about 6C hotter i.e. 37C at load vs 31C for 4TB drive.#2 missing holes in the middle of drive for mounting so may be a problem for some

In my case, the recommended method of mounting drives into the nas bays (ReadyNAS 204) involves a plastic clip that can only be used in the presence of these missing standard screw holes, so I had to mount it differently (which, for the record, is entirely possible and easy with this NAS, but don't count on that being universally true).

These drives are missing threaded holes for mounting it in a case!

so it doesn't continue to blue screen and return I/O errors.