Since you do not have a "K" model Core i7 Ivy Bridge CPU, the only thing you can do is to increase the BCLK frequency. However, everything is tied to the BCLK frequency like the PCI-e slot and USB ports.
The BCLK is set to 100MHz. Generally speaking, you can probably push to 105MHz, but the PCI-e slot and especially the USB ports are pretty sensitive to the BCLK frequency. Above a certain frequency and they may stop responding. Push it even a little too much and the USB ports can be permanently damaged.