Review on HighPoint Rocket 640L Lite - 4-Port PCI-E 2.0 x4 SATA 6Gb/s RAID Controller by Nhyiraba Wilson

They plug into x4 PCIe slots but only use two lanes. Therefore, they should be advertised as x2 boards and not x4 boards. The maximum throughput of PCIe 2.0 with 2 lanes is 1 GB/s, which is half that of a 2 GB/s x4 card. This is quite sufficient for all conventional hard drives in existence today, the speed of which is around 150 MB/s at the fastest. However, this limits the performance of two or more fast SSDs, each of which can transfer data at over 500 MB/s. I am using a Sata II 4 drive board and have found that the board can handle all 4 drives simultaneously at their maximum speed with no problem. With this service the limiting factor is the drive and this board performs as well as the x4.