Can we use SSD on sata II 3 gbps port - can it affect its performance ?

Hi, everyone says recommended that you need to have SATA III (6GBPS) port to get maximus benefit of SSD. What I see that most of the consumer grade SSD can only give 400Mbps to 500mbps output which is still far less than 3GBPS output of SATA II port. So my mother board only have Sata II port , it means if I use SSD , I will not get much benefit.
Is it true ?

Or because 3GBPS which is theoretical limit is still lot more than actual speed of SSD so I should not worry ?