The Controller Lineup
As mentioned on the previous page, the first motherboards and add-in cards to support USB 3.0 employed NEC’s PD720200 controller. A number of other players have joined the game since then, though. All of the motherboards shipping today use newer logic like ASMedia's ASM1042 and Etron's EJ168. Others, based on AMD's A75 chipset, employ integrated USB 3.0 support. There are also Renesas controllers that build on NEC's previous design to reportedly reduce power consumption by 85 percent. VIA has its own SuperSpeed controller, too.
Today we're testing the ASMedia and Etron models. Both USB 3.0 host controllers map two ports to a single PCIe x1 lane, allowing motherboard vendors to easily add USB 3.0 connectivity using chipset-based PCI Express.
A third-party controller is mandatory if you buy an Intel-based platform with USB 3.0 support because Z68, P67, and X58 (all of the enthusiast-oriented platforms in the company's portfolio) fail to include native USB 3.0 support. X79, expected next month, doesn't include this functionality either.
Intel’s delayed support is a disappointment, particularly because AMD is already wrapping integrated USB 3.0 into its A75 chipset for Llano-based APUs (unfortunately, you'll have no such luck with the 990FX chipset built to support Zambezi-based processors).
You have to be careful, though. AMD enables the Socket FM1 ecosystem through a pair of Fusion Controller Hubs, A75 and A55. The lower-end A55 solution is stuck with 3 Gb/s SATA support and it doesn't accommodate USB 3.0 data rates. In very entry-level systems, those probably aren't problems. But if you're really performance-focused, stepping up to A75 gets you six SATA 6Gb/s ports, FIS-based switching, and four USB 3.0 ports.
|Feature||AMD A75||AMD A55|
|Platform||Socket FM1||Socket FM1|
|SATA Connectivity||6 x SATA 6Gb/s||6 x SATA 3Gb/s|
|Software RAID||0, 1, 10||0, 1, 10|
|General-Purpose PCIe||4 x PCI Express 2.0 lanes||4 x PCI Express 2.0 lanes|
|UMI (Connection To APU)||Four-lane PCIe + DisplayPort||Four-lane PCIe + DisplayPort|
|33 MHz Legacy PCI||Up To Three Slots||Up To Three Slots|