The Brazos platform is AMD's ticket to the netbook platform and other ultrathin notebooks. AMD has always maintained that they didn't see a point to enter these segments previously as they couldn't deliver their balanced platform perspective and nor is the competition doing such. Sure, Intel was ruling the roost with low-voltage Core 2 Duo and Atom processors, but its accompanying graphics was abysmal and often needed third-party intervention from AMD or NVIDIA to better equip this class of systems for multimedia needs. AMD on the other hand, was busy attacking the desktop front and didn't have an ideal architecture or resources to counter Intel's move into the compact notebooks space.
Brazos will finally plug this gap quickly and will do so with a more optimized CPU architecture and a decent DX11 GPU for a balanced solution - thus the Ontario APU design was born. This 9W TDP part targeted at netbooks and ultrathin notebooks will be complemented by a more powerful Zacate 18W APU variant for more mainstream notebooks and desktops.
The basic building blocks for both the Ontario and Zacate APU come in the form of the Bobcat CPU core architecture. This purpose designed core attacks the low power computing needs, as seen in the below diagram. It's also modular in nature allowing further cores to be fused together to create more options for various price and TDP points. For example, the Ontario is rumored to come in either single or dual-core variants (basically two bobcat cores) while the Zacate will be a faster dual-core processor. AMD can create further APU models with more cores if it requires, but for now, these two models are official.
Of interest is the out-of-order execution pipeline of the Bobcat architecture which places it ahead of the Intel Atom processor. All things being equal, the out-of-order pipeline (used by most mainstream processors) immediately brings about better processing performance than an in-order execution pipeline adopted by the Intel Atom processor. Plus, the sub one-watt operation of the core is again ideal for very compact form factors and devices. In fact, this core is likely the ideal candidate for the tablet market when it matures somewhat with more developmental prospects. Currently the tablet market is just too fragmented for AMD to make any significant push on its own.
Having talked about the CPU portion in these APUs, the GPU portion would be most people's main interest - just what sort of graphics engine is AMD packing into them? The good thing is that for all the APU variants, AMD will stick to an Evergreen class (Radeon HD 5000 series) DX11 compliant GPU engine. Remember, AMD wants to deliver discrete-class graphics but it also has to maintain low power and price in this sensitive segment of the Ontatio and Zacate APUs. As such, both of them will be equipped with Ceder-derivate graphics engines (essentially Radeon HD 5450 class). That doesn't sound very exciting, but it fulfills the design specs of having a discrete-class graphics built-in to the chip (with a low TDP to boot). Again, even GPU engines are rather modular in nature and like the CPU portion, they can be scaled if required.
So now that we're better acquainted with the basic design and specs, here's a slide from AMD that depicts what sort of needs the Brazos platform is designed to address and to better manage expectations of end-users:-