We've confirmed that standard SATA 6Gb/s PCI Express Card adapters using the ASMedia ASM1061 (Asmedia 1061 SATA Host Controller) are working natively in OS X (10.6.8 and 10.7). So if your motherboard only has SATA 3Gb/s ports, you can now expand your system with faster 6Gb/s internal ports! Special thanks to notshy for the testing and info!
This year marked the first widespread distribution of SATA 6Gb/s. In fact, most 2011 H67/P67/Z68 motherboards are packing SATA 6Gb/s ports by default alongside the industry prevalent SATA 3Gb/s ports. This allows for double the data transfer speeds.
Syba 2 Port SATA 6Gb/s PCI-Express x1 Card
OCZ Vertex 3 SATA 6Gb/s MLC Internal Solid State Drive (SSD)
Corsair Force Series 3 SATA 6Gb/s Internal Solid State Drive (SSD)
Seagate Barracuda 7200.12 SATA 6Gb/s Internal Hard Drive