AMD's Graphics Core Next Preview: AMD's New GPU, Architected For Compute

We’ve just returned from sunny Bellevue, Washington, where AMD held their first Fusion Developer Summit (AFDS). As with other technical conferences of this nature such as NVIDIA’s GTC and Intel’s IDF, AFDS is a chance for AMD to reach out to developers to prepare them for future products and to receive feedback in turn. While AMD can make powerful hardware it’s ultimately the software that runs on it that drives sales, so it’s important for them to reach out to developers to ensure that such software is being made.

AFDS 2011 served as a focal point for several different things going on at AMD. At its broadest, it was a launch event for Llano, AMD’s first mainstream Fusion APU that launched at the start of the week. AMD has invested the future of the company into APUs, and not just for graphical purposes but for compute purposes too. So Llano is a big deal for the company even though it’s only a taste of what’s to come.

The second purpose of course was to provide sessions for developers to learn more about how to utilize AMD’s GPUs for compute and graphics tasks. Microsoft, Acceleware, Adobe, academic researchers, and others were on hand to provide talks on how they’re using GPUs in current and future projects.

The final purpose – and what is going to be most interesting to most outside observers – was to prepare developers for what’s coming down the pipe. AMD has big plans for the future and it’s important to get developers involved as soon as is reasonably possible so that they’re ready to use AMD’s future technologies when they launch. Over the next few days we’ll talk about a couple of different things AMD is working on, and today we’ll start with the first and most exciting project: AMD Graphics Core Next.

Graphics Core Next (GCN) is the architectural basis for AMD’s future GPUs, both for discrete products and for GPUs integrated with CPUs as part of AMD’s APU products. AMD will be instituting a major overhaul of its traditional GPU architecture for future generation products in order to meet the direction of the market and where they want to go with their GPUs in the future.

While graphics performance and features have been and will continue to be important aspects of a GPU’s design, AMD and the rest of the market have been moving towards further exploiting the compute capabilities of GPUs, which in the right circumstances are capable of being utilized as massive parallel processors that can complete a number of tasks in the fraction of the time as a highly generalized CPU. Since the introduction of shader-capable GPUs in 2002, GPUs have slowly evolved to become more generalized so that their resources can be used for more than just graphics. AMD’s most recent shift was with their VLIW4 architecture with Cayman late last year; now they’re looking to make their biggest leap yet with GCN.

GCN at its core is the basis of a GPU that performs well at both graphical and computing tasks. AMD has stretched their traditional VLIW architecture as far as they reasonably can for computing purposes, and as more developers get on board for GPU computing a clean break is needed in order to build a better performing GPU to meet their needs. This is in essence AMD’s Fermi: a new architecture and a radical overhaul to make a GPU that is as monstrous at computing as it is at graphics. And this is the story of the architecture that AMD will be building to make it happen.

Finally, it should be noted that the theme of AFDS 2011 was heterogeneous computing, as it has become AMD’s focus to get developers to develop heterogeneous applications that effectively utilize both AMD’s CPUs and AMD’s GPUs. Ostensibly AFDS is a conference about GPU computing, but AMD’s true strength is not their CPU side or their GPU side, it’s the combination of the two. Bulldozer will be the first half of AMD’s future APUs, while GCN will be the other half.