How Do I Find The Hardware Block Read Size for My Hard Drive?

I'm trying to figure out the optimal size for a large copy from my hard drive using dd. I'm trying to figure out what the best blocksize to use it, which I would assume is the hardware block size for that drive.

The lsblk command is great for this:

lsblk -o NAME,PHY-SeC

The results:

NAME   PHY-SEC 
sda        512 
├─sda1     512 
├─sda2     512 
└─sda5     512 

Linux exposes the physical sector size in files /sys/block/sdX/queue/physical_block_size. Although, to get the best performance you should probably do a little testing with different sizes and meassure. I could not find a clear answer in that using exactly the physical block size would get the optimal result (although I assume it cannot be a bad choice).