The R9 390 STRIX has a 1050MHz core (1000MHz reference) and the R9 390X STRIX is clocked at 1070MHz (1050MHz reference). Both models have 8GB GDDR5 memory clocked at 6000MHz.
It features a huge monolithic aluminium fin-stack heatsink, to which heat drawn from the GPU is fed by four 10 mm thick nickel-plated copper heat pipes. This heatsink is ventilated by three 100 mm spinners. This heatsink has contact bases even over the card's 8-phase VRM, and a base-plate that draws heat from its 16 GDDR5 memory chips, that make up 8 GB.
Via: TPU