Every couple of years CPU manufacturers begin following a new trend. The first trend was the race for GHz, which died out with Intel’s Netburst architecture. The second trend, which is the one we are currently in, is the race for multiple cores. The past two years have seen a huge increase in the number of cores that are on a CPU. From single cores, to dual cores, we are now on the stage of quad cores and on the eve of octal-cores.

AMD has forecasted that by 2010 we will see the multi-core trend come to an end. Instead, AMD will begin to focus heavily on Fusion technology, bringing about the birth of APUs (Accelerated Processing Units).

All of this might sound a little confusing at first, so we will summarize it as simply as we can. Fusion is a technology that fuses both the CPU and GPU into one package. Processors based on Fusion technology are called Accelerated Processor Units. Accelerated Processors will be initially used for mobile devices, such as PDAs and Cell Phones. This is primarily because the fusion of a GPU and CPU will be able to reduce power consumption and also increase efficiency. Over time, APUs will evolve to be used in computer systems from entry-level systems to high performance workstations.

APUs (Fusion CPUs) will use a modular approach and can be classified into two categories. In the first category, Fusion CPUs will be general and geared for a variety of applications. The second category of APUs will be targeted towards different segments of the market and will be application specific. Basically, AMD’s vision for APUs is that they will be a set of building blocks that can be mixed and matched together to create specific processing capabilities depending on the end market. This means that, in time, APUs (Fusion processors) will be found in a variety of devices from PDAs to high-end servers. It is important to remember, however, that initially Fusion will focus heavily on mobile solutions and from there make its debut into the mainstream.

Accelerated Processors can also be used with AMD’s Torrenza platform. This means that you can have a Fusion processor plugged into a Torrenza platform along with another application specific coprocessor. This means that your computer can be very application specific to have huge performance benefits in a specific application. In theory, a general Fusion processor could also be used along with an application specific coprocessor allowing the best of both worlds. As can be seen, AMD Stream Technology can also be used in accordance with Torrenza and Fusion. Fusion, Stream, and Torrenza combined come out to equal equal AMD Accelerated Computing.

For Fusion processors, integration of the GPU and CPU will happen at the silicon level. With APUs, AMD aims to take advantage of their integrated memory controller and the flexibility of HyperTransport. The role that ATI will play in Fusion processors is vital as the GPU will ultimately be very closely tied with the CPU.

Fusion Processors are a very radical change compared to traditional processors. Some might even consider it a reinvention of the microprocessor. Despite how promising the technology may seem at the moment, AMD still has a long and hard road ahead of them. Their ambitious view of the Fusion Processor penetrating all levels of the market will require large amounts of money, work, and time. In the course of the next year we hope that we will see more practical example of this architecture working on some prototypes. Since the technology is still in its very early stages, we expect AMD to make quite a few changes to it before we actually see it debut. Until that time, we still have AMD’s quad-core Barcelona to look forward to.