All high end graphics cards can be overclocked, it's just a matter of some being capable of being overclocked more than others due to limitations with the cooling system. Which is why they sell models with liquid cooling and aftermarket liquid coolers for them. With a stock configuration it's likely the Gigabyte can achieve a HIGHER overclock than the EVGA since it has a lower performance cooler. Then again, it might just be a dice roll either way but the G1 gaming cards DO have consistently better reviews than the EVGA cards for the GTX 970 and 980.