Your benchmark results are normal.
Your motherboard only has SATA 2 (3Gb/s) ports.
You need a motherboard that has SATA 3 (6Gb/s) ports in order to get maximum advertised speeds from your SSD.
Is it worth buying a new motherboard for SATA 3 and also do i need SATA 3 cables, the cables i got now are these http://www.komplett.no/k/ki.aspx?sku=300720
( sorry for norwegian)