With its emergence as the new standard for high-speed portable devices, USB 3.0 performance on a modern motherboard needs to be good to ensure that data transferral bottlenecks aren't created.
We tested USB 3.0 performance using an ADATA SP300 SSD connected to an Icy Box IB-223StU3 USB 3.0 enclosure (ASMedia ASM1051 controller). ATTO was the benchmark used.
Using ASMedia's ASM1042 host controllers, USB 3.0 performance on the Rampage IV Black Edition is distinctly average. Fatigue to our test SSD has probably shaved a few MB/s from the Rampage IV Black Edition's transfer rate.
Also valid is the possibility that the board's ASM1184e PCI-E lane-splitting chipset may be introducing additional latency and losses into the PCI-E subsystem which has had a small effect on the performance of controllers feeding off it.
what an amazing board – very very expensive though!