AMD details Bulldozer and Bobcat innovations

Chip firm reveals core designs that will power processor chips coming next year

Bulldozer and Bobcat will be powering AMD chips 'for years to come'

AMD will today present details of two new processor core designs at the Hot Chips conference in California. The cores, Bulldozer and Bobcat, will power AMD's processor chips for 2011 in the mainstream and power-efficient categories, respectively, plus further chips for years to come.

The two cores are both new designs from the ground up but target separate market segments with different capabilities. Bulldozer will appear first in chips for servers but also later in PCs and laptops, while Bobcat will form the CPU core in AMD's first fusion chip and will target netbooks and other portable devices.

In a press briefing ahead of the Hot Chips conference, AMD said the new cores showed that innovation within the firm is alive and well, and that these designs will form a solid foundation for AMD products for years to come.

Bulldozer is the 'heavy lift' core, set to debut in the 16-core Interlagos server chip early in 2011. It features a number of instruction set extensions and is built using 32nm process technology.

It will also power mainstream client products, appearing in other chips with a smaller number of cores.

Each Bulldozer core comprises two integer execution units plus some shared components, such as floating-point execution units, which reflects the fact that over 80 percent of compute tasks are integer based while floating point is used only occasionally.

This means that each Bulldozer module functions as two processor cores as far as software is concerned, but is smaller and consumes less power than the conventional approach of putting two complete monolithic cores side-by-side on a chip, according to Chekib Akrout, senior vice president of AMD's Technology Group.

"We've done significant research into analysing workloads, looking at what needs to be shared and how to maximise performance," he said.

Akrout said this approach is more efficient than Intel's Hyper-Threading technology, which turns each core into two virtual processors that have to share all on-chip resources.

AMD details Bulldozer and Bobcat innovations

Chip firm reveals core designs that will power processor chips coming next year

To create a processor chip, multiple Bulldozer modules will be combined with a shared L3 cache unit and memory controller, with eight modules required for a 16-core chip.

From a performance perspective, AMD expects Bulldozer to meet the same power envelope as its current server chips based on Magny-Cours, but deliver 33 percent more cores and an estimated 50 percent increase in throughput.

Meanwhile, Bobcat has been designed as a small and highly efficient x86 core for netbooks and other portable devices, and AMD seems to be lining it up to compete against Intel's Atom chips in this space.

Akrout claimed that Bobcat's support for out-of-order execution gives it "a significant advantage against Atom". It also has support for virtualisation, 64bit instructions, and SSE 1, 2 and 3.

"Our estimates are that this represents 90 percent of the performance of our current mainstream CPU, and that's in half the silicon area and a fraction of the power," Akrout said. Each core is said to consume less than one watt.

Bobcat's first appearance will be early in 2011 in the Ontario chip, AMD's first Fusion product, which will see two Bobcat cores paired with a GPU to make what AMD calls an accelerated processing unit (APU).

The core design is described as 'highly synthesisable' by AMD, which means it is not tied to a particular chip fabrication technology and can easily be combined with other components to produce system-on-a-chip (SoC) products such as Ontario.

"Fusion is all about our future, the combination of our CPU and GPU which really optimise our compute power and get us to the next chapter in terms of visual computing performance. Only AMD can deliver the CPU and GPU combination that will be the future of computing," said Akrout.

Further details of Bulldozer and Bobcat will be disclosed during the Hot Chips conference, AMD said.