OpenCL: Bitmining, LuxMark, And RatGPU
Even though bitcoins themselves have seen some lively discussions of late, and there’s specialized equipment that’s much more efficient for mining them than graphics cards, mining still makes for a great benchmark. AMD is clearly the winner here. However, the two graphics card generations perform almost the same. The Radeon R9 290X’s inability to pull ahead is due to PowerTune. The temperature and power targets are reached quickly, and, once that happens, clock rates take a big hit.
For what it's worth, AMD’s new flagship shares this fate with Nvidia. The GeForce GTX Titan reacts just as badly under this kind of load. From where we sit, AMD clearly optimized the R9 290X for gaming. Under a constant, heavy compute load, Hawaii stands no chance of delivering the same exceptional performance.
It’s no secret that the OpenCL-based LuxRender software has always been one of AMD’s strong suits. Its OpenCL implementation is fairly well optimized and serves as a good demonstration of Nvidia’s lack of commitment to this platform. Unfortunately, the Radeon R9 290X’s advantage over the 7970 GHz Edition isn’t as large as it should be based on each card's technical specifications. Once more, PowerTune hits the brakes and keeps Hawaii from achieving its full potential (or self-combusting). This is somewhat sad to see, really.
ratGPU performance is a whole other story, which is to say that the pattern of graphics cards that have an advantage changes due to ratGPU’s completely different architecture. The older AMD Radeon HD 6970’s result is especially noteworthy in this benchmark, since it practically destroys the rest of the field. The current Radeon graphics cards have to be content with the better part of the middle, and the R9 290X doesn’t change this.