ASUS has, just like Gigabyte, presented the first motherboards supporting the new storage interface SATA 6Gbps. Compared to today’s SATA II (3Gbps) interface the newest SATA standard has twice the theoretical transfer speed and enables storage units to reach new levels of performance. ASUS P6X58 will be one of the first motherboard to support the new interface, but also USB 3.0. But just like the first USB 3.0 controllers there is a weak spot in the SATA 6Gbps support.
The first SATA 6Gbps controller comes Silicon Image and is used by both ASUS and Gigabyte, but it has a bottleneck. Just like NEC did with its first expansion card for the USB 3.0 interface it has limited the speed of the SATA chip by connecting it through PCI-Express x1.
This means that the SATA 6Gbps controller is limited to transfer rates below 250MB/s, which really puts things back to SATA 3Gbps speeds. ASUS has demonstrated speeds up to 337MB/s at Computex so exactly how things are with Silicon Image’s chips is a bit uncertain.
“EVGA replied it had looked into the first generation Silicon Image chipset but reckons that since it’ll be only connected via a PCI-Express x1 interface, it’ll likely be bottlenecked.”
EVGA has decided to put the new SATA interface on hold for this very reason. Also, few storage units can make use of the SATA 6Gbps interface making it another reason for EVGA to wait.
