So far from the various leaks out on the net and AMD’s official releases, all we’ve found out are the clock speeds and shader counts. The clock speed has been pegged to 1266 MHz with a total of 36 CUs and 2304 Shader Processing Units. Now that GPU-Z has added RX 480 support, we’re finding out for the first time, what the rest of the chip looks like.
According to the leak, the RX 480 features 144 TMUs and 32 ROPs. The number of TMUs is expected as it’s the same ratio throughout most of GCN. From the ROP count, we can really see how Polaris 10 has mainstream roots. Despite having only 256 fewer shaders, the GPU only has half as many ROPs as the R9 390. This will set a hard cap rasterization operations.
However, the good news is that AMD has tweaked a lot with GCN 4, likely improving real world ROP performance. There is also the new primitive discard accelerator which will help reduce the ROP workload. The higher clock speeds will also help offset this, leaving us with a total of 40.5 GPixels/s. Given leaked benchmarks, I expect it may match the 64 ROP GCN cards in real world performance. Now we just have to wait a couple days and see how Polaris will really perform like.
