All SATA cables are not made equal. However, a quality "SATA II" cable will work just fine with SATA III and offer all of the same bandwidth. Some cables provided with some motherboard mfgs are cheap and may inhibit performance - even on SATA II. For my SSD reviews, I have been using the (labeled) SATA III cables provided by Intel as I trust their component quality. I would assume cables that come with SSDs would be of sufficient quality from mainstream manufacturers. I don't think there is really a design difference in what are labeled as SATA II and SATA III cables, they just have better materials (kinda like binned NAND or processors, same design, different possible speeds).