Propably you connected the drive to integrated m.2 port which mostly only supports PCIe 2.0 x2 which ends up in your numbers. You can try an add on card which supports PCIe x4. But with Z97 you need to share lanes with your graphics.
You have a lot of ECC and CRC errors, I would call Samsung Support and ask what to do.
My old Samsung 830 has:
Host Writes : 20695 GB
C3 200 200 __0 000000000000 ECC Error Rate
C7 253 253 __0 000000000000 CRC Error Count
Try new Magician here http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/support/downloads.html
The restoration tool should be intergrated now.