Gigabyte’s Controversial “USB3.0 Turbo” Mode
 

As I mentioned in my initial testing, there seems to be a lot of debate concerning Gigabyte’s design decisions. Let me refresh your memory briefly. Both the SSUSB controller, and the SATA3 controller can communicate with the CPU in two different ways, and the user can choose their preference. If maximum performance of these devices is your priority, you can turn on “Turbo” mode in the BIOS. This will interface the controllers with the CPU via one of the 16 PCIe 2.0 lanes on the CPU die itself. The downside of this approach is that your PCIe graphics card bandwidth will get knocked in half (although that’s usually still plenty). If you need fast, but not the absolute fastest SSUSB/SATA3 performance, and you prefer your graphics card to have maximum performance, you can turn off Turbo mode in the BIOS, and the SSUSB/SATA3 controllers will interface with the CPU via a PCIe 1.1 lane in the P55 chipset via the Direct Media Interface (DMI). As we saw in my initial testing, the Turbo mode did have some good performance advantages. The one situation in which the user will not have an option is when running dual graphics cards. In this configuration, the system will run 8 PCIe lanes to each graphics cards, and force the SSUSB and SATA3 controllers to use the non Turbo interface.

http://www.overclockers.com/gigabyte...-pushed-limit/