Use rsync with z option.

-z,         --compress              compress file data during the transfer
            --compress-level=NUM    explicitly set compression level
            --skip-compress=LIST    skip compressing files with suffix in LIST

This will increase speed of transfer.

Use rsync with z option.

-z,         --compress              compress file data during the transfer
            --compress-level=NUM    explicitly set compression level
            --skip-compress=LIST    skip compressing files with suffix in LIST

This will increase speed of transfer over the network. So most probably not useful in your case.

After some more reading I realized that, We should not use the ‘-z’ flag when copying data from one local hard drive to another, it increases overhead. Thank to comment from @FakeName.