sectorsize is a tiny command line I made to detect the Physical and logical sector size of your hard disk.
sudo sectorsize /dev/diskX
Physical sector size: 4096 Logical sector size: 512
Physical sector size: 512 Logical sector size: 512
OSX seem to show always 512-byte as "logical" sector size (*because is a standard?), but you can see that AF drive show a physical 4096-bytes sector, and probably this mean that this drive use the 512e tecnology (512 bytes emulation).
*NOTE: hard disk with 4K use firmware to emulate 512 sector size....as the OS wants..
Thanks to verdant for the tests made