GPU Computing
The Graphics Core Next architecture is supposed to provide significant GPU computing performance compared to previous and current GPU designs. We can test this using synthetic testing tools that use DirectCompute or OpenCL to perform math or graphics operations and our results do indicate a significance performance gains over two GTX460 cards, however real world applications are important.
Although this is progressively changing with newer applications appearing, such as Corel WinZip 16.5 which will support OpenCL, most applications that utilise GPU Compute capabilities are multimedia oriented.
One of the more popular uses for AMD Radeon's GPU computing in the enthusiast community is Bitcoin Mining. For those who have not heard of Bitcoin in a broad sense it is a virtual currency and some users 'mine' for Bitcoins in the way that a prospector or miner may search for gold.
In order to measure the performance we tested Bitcoin using the common Guiminer mining tool but we were unable to engage mining for only 15 seconds at a time before the process failing due to errors in the calculations.
We tested the Phoenix and cgminer tools and had the same result with several variations of settings, invalid hashes for the computations. Once a mining tool supports the GCN architecture, we will be able to get a real world intensive indication of GPU compute performance for consumer use in a non-graphics or video application.
In addition to the invalid hashes, we could not exceed 400 Mhash/s throughput on the mining operations. This is equal to current technology and should be much higher for the HD7970. Fans of Bitcoin Mining we spoke to had predicted the architecture and specifically a HD7970 should theoretically be able to achieve 800Mhash/s with the right software
Due to the low performance and invalid hashes with all three mining tools, we left out Bitcoin from our formal results and will revisit when we publish our first update once new drivers and software are available. Due to their architecture as consumer graphics cards, current NVIDIA GeForce is not suitable for the task of Bitcoin mining.
