VisionTek (www.visiontek.com) has launched the US$32.99 Four Port USB 3 PCI3 card. It offers plug and play operation with Macs running OS X 10.8.2 and later.
According to the folks at VisionTek, it can deliver benchmark test-confirmed 356MB/s Read and 338MB/s Write data transfers. It can also be used to power USB devices or charge them without needing an AC adapter. Each port provides 900mA of power.