Brazos Platform: Over 90GFLOPS of Compute Power
X-bit labs: How high the projected performance of the Ontario/Zacate in terms of GFLOPS is? Was it actually a major priority to achieve certain levels of performance?
Godfrey Cheng: With Zacate we are looking at over 90GFLOPS, which is pretty impressive for a chip of that thermal design power and size... Certain performance goals were not a major a priority.
X-bit labs: How many memory channels are inside Ontario and Zacate?
Godfrey Cheng: Ontario and Zacate have single-channel DDR3 memory controller.
X-bit labs: Is there going to be a performance limitation because of memory bandwidth?
Godfrey Cheng: For Ontario/Zacate we are adding PC3-10600 (DDR3 1333MHz) support, it is a fairly robust memory controller and for the vast majority of applications we see no problems in going single channel.
Indeed, in case of Brazos platform AMD decided not to squeeze all the performance possible out of its chips, but focused on making them as small as possible, as power efficient as possible and as feature-rich as possible. The result is obvious: the 9W dual-core Ontario chip delivers DirectX 11 graphics; parallel compute functionality; support for hardware decoding of various video formats, including Blu-ray; as well as relatively modern processor micro-architecture that is at least a decade younger compared to the heart of Intel Atom.
X-bit labs: Is memory controller of Fusion-series chips similar to those used today, or you tweaked them somehow?
Godfrey Cheng: If you look at Llano, then memory controller is quite different to Ontario/Zacate. We have also done some tweaks for GPU in Llano. We try to design the best memory controller we can for each of our products. That is all we can share at this time.