Never bothered to test an HDD before but I did benchmark my Samsung 840 SSD (256GiB) when I first installed it. Got numbers pretty much identical to those on the box:
Read 540MB/s (4KB Random 96K IOPS)
Write 250MB/s (4KB Random 62K IOPS)
As Celtic says, your 'seq' is sequential data while the 4K/512K are data blocks (of that size) randomly spread over the drive. Also, you might want to free up some space on your SSD if it is 94% full. I think a good rule of thumb for mechanical disks is to keep 10% free. For solid state drives you might want more to avoid excessive write amplification.