AMD Radeon R9 380X “Tonga” only with 256-bit memory bus

After more than a year, it is time for the graphics circuit Tonga to scale up from its cut-out design, which was first introduced with the Radeon R9 285 and which in turn amounted to a refreshed R9 380. Now it turns out that it will not be true what many have expected.

According to sources at SweClockers, the upcoming Radeon R9 380X will be equipped with a scaled-up variant of Tonga, where the number of stream processors will increase from 1,792 to 2,048. So far, previous information is correct, however, there will be no lift for the memory bus.

Instead of 384 bits, the width of the Radeon R9 380X lands at 256 bits, that is, the same as the R9 285/380. In addition to the fact that there will not be a huge increase in bandwidth, this means that the amount of memory remains at 2 or 4 GB, instead of stepping up to 3 and 6 GB respectively.

It has long been speculated that Tonga actually has a bus width of 384 bits and why AMD does not choose to activate the entire package is not clear. One explanation could be to keep power consumption down, but also because the whole bus is not needed in combination with Tonga’s memory compression.

It is also possible that the reasons are an attempt to keep prices down. This through two parts. The first is that the number of memory circuits that need to be purchased is kept down. The second is that partner manufacturers do not need to develop new circuit boards, but can use the same as for the Radeon R9 380 and thus also benefit from economies of scale in the production stage.

Finally, there are uncertainties about the graphics card’s exact clock frequencies, but they are not expected to be far above the Radeon R9 380. Where AMD lands officially, on the other hand, probably has no major significance, as most of all variants in stores can be expected to come with increased frequencies directly from the factory.

An exact launch date for the Radeon R9 380X does not yet exist, but the only thing currently communicated is the end of October. The graphics card will be wedged between R9 380 and R9 390, which speaks for a price tag of around SEK 3,000.