To give that out-of-the-box edge over its competitors, Gainward decided to soup up their Ti4600 cards a little bit. Similar to what they have done to other Golden Sample cards based on other chipsets, they have set the Golden Sample Ultra/750XP's from its default 300MHz core and 650MHz memory to 310MHz and 680MHz respectively. While it may seem like Gainward "cheated" by overclocking these chipsets, it is far from so. Gainward just managed to work things around with NVIDIA to supply them with better yield of their Ti4600 chipsets. Gainward just handpick those that could run at 310/680MHz and then uses them in their Golden Sample cards.
Review Link : HardwareZone