controller cards

Most USB 3.0 controller cards available on the market today utilize the PCIe x1 interface. With a maximum theoretical bandwidth of 5Gbps, it is possible that these controllers could bottleneck performance when transferring data between, say, multiple SSDs, HDD arrays, and high-performance USB 3.0 flash drives. We take a look at HighPoint's RocketU 1144 PCIe x4 USB 3.0 controller card. Its utilization of PCIe x4 promises 20Gbps of bandwidth. Is this enough to satiate even the most demanding transfers?