GPUs (graphics processing units) are a favorite topic on this blog. It is an innovative and powerful computing idea with an almost awkward origin: the graphics card, which has in the past been used to perform calculations necessary for visual rendering, is now used in GPU applications to help the processor perform millions of general computations. In effect, the GPU becomes a specialized processor in the computer.
GPU products have been soaring in popularity recently, especially for scientific uses. But the CPU-GPU arrangement still retains the old CPU-graphics card relationship. That is, the way a CPU and GPU are connected is still the same way that a CPU used to interact with a graphics card, through the PCI-E slot on the motherboard. GPUs are fast, but their speed is limited by this type of connectivity, a remnant from the days when GPUs were just graphics cards. In effect, PCI-E communication between the GPU and motherboard is a bottleneck on performance.
AMD is tackling this problem head-on with their upcoming Fusion line of processors. Instead of connecting a GPU to to the motherboard like an add-on card, AMD proposes to make the GPU part of the same silicon chip as the CPU, eliminating the need for PCI-E communication. They have dubbed this combination of CPU and GPU technology “Accelerated Processing Unit” (APU).
Currently, the AMD Fusion processor is going to be released for the consumer market in desktop and laptop computers. But, while AMD is working on bringing this technology to server boards, many issues (mostly with coding) need to be resolved before this can happen, as John Fruehe of AMD explains in his blog article, “Fusion for Servers”.
Nevertheless, this innovation carries some promise for the future evolution of GPU technology. It has the potential to eliminate the PCI-E bottleneck and make that remnant of GPU’s original function as a graphics card a thing of the past.
But this won’t be easy for AMD. Although it has the advantage of being the only processor manufacturer to also produce graphics cards (AMD bought ATI in 2006) NVIDIA is still the leader in GPU technology. Many commercial battles will still be fought for the future of GPUs between these and other manufacturers, among them the competition between the coding languages of CUDA and OpenCL.
Despite these hurdles, AMD’s plans for using Fusion processors in servers is an nascent idea with a lot of potential to improve the GPU market and make computers – and supercomputers – even faster.