The picture could be real but its very easy to adjust your memory timings and get speeds like that, however it will produce mostly rejected shares.
For the AMD R89 390, with the 1500 MHz, the limiting factor is already the core speed. So adjusting the memory does not help.
I am not talking about memory clock, I am talking about memory timings. You can adjust them and get it to show like 1000-2000H/s however it will produce nothing but rejected shares or crash.