If the video isn't an outright fake, I'm going to hazard a guess on what is going on here. It is almost certainly doing a solo running benchmark run with 0 generation DAG, which fits into the card's UltraRAM.
You'll never achieve that kind of a number any other way. Even if you put in QDR2 SRAM modules in those DIMM slots it won't help you because IIRC you can only get 288MB worth of those in - far less than the 3GB+ you need for current DAG size for ethash based coins.