Announced at AMD's 30 Years of Graphics And Gaming celebration last month, and newly released this week, the Radeon R9 285 is AMD's first major card launch since the dual-GPU R9 295X2 was released back in April. Indeed it is their new silicon since Hawaii debuted with the Radeon R9 290X in October of last year. All indications are however that this new card isn't a major architectural revision, instead relied on the tried and tested GCN architecture which served them well through the 7000-series and into the 97 & R9 era, perhaps waiting for a mature 20nm manufacturing node to become available. As a consequence major performance gains from this new GPU, codenamed Tonga, may be too much to expect; AMD have surprised us in the past though.

The Tonga Pro GPU within each R9 285 has specifications quite similar to the (Tahiti Pro-based) Radeon R9 280 it obstensively replaces. In addition to being based on the same 28nm lithography process it also features the same number of shaders, tessellation units, ROPs and an equivalent Z Stenzil Buffer depth as its predecessor. It is also clocked slightly lower and has a narrower memory bus (256bit vs 364bit), and less VRAM overall (2GB vs 3GB). In fact, the only value for which it exceeds the R9 280 is in memory bandwidth (5.5 Gbps vs 5 Gbps).