As we mentioned on page two, MSI's GeForce GTX 660 Ti Power Edition overclocks really well. We squeezed out an additional 150 MHz from the core (taking its GPU Boost typical frequency to 1325 MHz) and an extra 250 MHz from the memory, yielding a 7008 MT/s data rate. Additionally, we're throwing in the Radeon HD 7950 Boost Edition's results.
The overclocked GeForce GTX 660 Ti approaches the existing GeForce GTX 670 in some games. In others, like Batman, the overclock isn't as effective. By the numbers, though, the GK104-based GTX 660 Ti looks to be a reasonably flexible overclocker.
As for AMD's Radeon HD 7950 Boost Edition, its higher performance certainly seems to warrant an updated BIOS by putting distance between the lowest-end Tahiti-based board and the fastest Pitcairn-based product. We've been saying this from the start. The question is: what other effects do higher clocks and voltages have on HD 7950 boards?