Radeon R9 390X

Hawaii-based graphics cards, the Radeon R9 290 and R9 290X, introduced in late 2013, are arguably one of the most successful AMD products in the history of its graphics division, and before that, ATI. The Radeon R9 390X was essentially a rebrand of this series with improved performance.

Grenada/Hawaii is manufactured on a 28nm process and contains 6.2 billion transistors. The Radeon R9 390X is equipped with a fully unlocked version of the chip, which includes 2816 shader ALUs (stream processors), 174 texture units and 64 ROPs. The GPU belongs to a version of the Graphics Core Next architecture, informally referred to as GCN 1.1.

The GPUs in the Radeon R9 390X differed from the Hawaii chips of the previous wave in that the matured technical process made it possible to raise clock frequencies without going beyond the TDP that were set earlier (typical power consumption of the R9 390X is estimated at 275 W, although AMD probably embellished the picture). The GPU frequency limit has been increased from 1000 to 1050 MHz - thus AMD has included in the official specifications the factory overclocking characteristic of the original design versions of the Radeon R9 290X, which have appeared since the official premiere of the latter.

More curiously, the RAM has also been overclocked, which in the R9 390X is clocked at 1500 (6000) MHz. As a result, the R9 390X achieves the highest memory bus bandwidth of any GDDR5-equipped graphics card at 384Gbps. Only the R9 Fury X with HBM memory (512 Gbps) has more. For the GeForce GTX 980 Ti, this parameter is 336 Gb / s.

Such a load was not originally intended for Grenada / Hawaii memory controllers. After all, AMD once opted for a wide 512-bit bus precisely in order to be able to reduce its clock frequency to 5 GHz, and, consequently, to make RAM controllers smaller. In fact, this part of the ASIC in Grenada/Hawaii occupies a smaller area than in the Tahiti chip (Radeon HD 7970, Radeon R9 280X).

Radeon R9 390X Specifications

In addition, the Radeon R9 390X received 8 GB of RAM - twice as much as the R9 290X, GeForce GTX 980 and even AMD's previously released flagship - Radeon R9 Fury X.