Every mention of the Radeon R9 380X states that this graphics solution has 2048 stream processors and 256-bit bus, next to 4 GB of GDDR5 memory type . However, some time ago, forecasters argued that physically, the full version of the GPU Tonga has a 384-bit bus.
Associates argue that in the case of the Radeon R9 380X all the cards will be equipped with a 256-bit bus. Accordingly, the amount of memory graphics card is unlikely to exceed 4 GB.
The motives of such a restriction is not disclosed, although it may be a desire to save on PCB design processing, concern about energy consumption and other economic considerations. Perhaps 256-bit bus will show itself worthy through the use of data compression technology. Frequencies Radeon R9 380X is unlikely to be much higher than the frequencies of Radeon R9 380.