HardwareCentral - AMD's Ambitious 'Fusion' Processor on Track

AMD's Ambitious 'Fusion' Processor on Track

Quad-Core With Graphics Due in 2011

February 11, 2010
By Andy Patrizio

Advanced Micro Devices opened the International Solid-State Circuits Conference (ISSCC) with a disclosure of its first chip under the "Fusion" banner, a project that introduces a new core design along with the graphics processing it acquired with ATI Technologies in 2006.

AMD (NYSE: AMD) is sure doing a lot with this chip: it is integrating the GPU cores, shrinking the die with 32-nanometer-process engineering, and making the leap to high-K metal gate (HKMG) transistor technology. All of this will show up with a desktop chip codenamed "Llano" and its notebook counterpart, "Sabine."

The one thing not being done is incorporating the new "Bulldozer" core design, which will be AMD's first major redesign since the 64-bit Athlon core came out in 2003. Since Fusion uses the old Phenom II core, there is no Level 3 cache to unify all the cores. Each has its own separate Level 2 cache.

The Fusion series introduces a new modular design methodology that AMD calls M-Space, which is meant to give the multiple cores in the CPU greater flexibility to operate independently.

Clock speeds in Llano are estimated to be around 3.0GHz, which will dynamically go up or down, along with voltages, as needed. It's similar to Intel's TurboBoost and power savings technology in the new Core i5/i7, which shuts off unused cores and gives the cores running a job more horsepower as needed.

The Llano processor has a new core power gating technology from the manufacturing process that lets AMD completely disconnect cores from the power grid when not in use. AMD claims that this will reduce power leakage as compared to older gating solutions by a factor of 10.

Moving to the high-K metal gate technology also helps. Intel noted that its Penryn generation of chips, the first to use high-K metal gate, ran much cooler than previous generations. Power leakage is what causes a chip to get hot.

Each Core Has a Power Meter

Each of the cores in the Llano CPU will come with its own digital power meter to measure the actual load of each core very precisely and deliver accurate information such as clock speed, voltage, and workload to the chip's power manager. As such, the chip knows precisely what all four cores are doing and their workloads and can adjust accordingly, shutting down cores doing little or no work and amping up the ones that need it.

It's a pretty ambitious chip, notes Jim McGregor, chief technology analyst at In-Stat. When AMD was tripped up trying to get "Barcelona" out the door in 2007, executives at the company told him their mistake was introducing too much change at once. However, he does not think they are doing it again.

"It does look very familiar when you think of everything they are trying to put on one die," he told InternetNews.com. "The significant difference is that they got over the difficulty with integrating multiple cores in Barcelona, and they have a very mature and very good graphics core. So in theory it shouldn't be as complex as Barcelona."

But it does look like quite a powerful chip for what's supposed to be a mainstream product.

"When they first introduced the Fusion concept, it was supposed to be a processor for the mainstream," said McGregor. "But when you look at what they are doing, you have to ask why is this aimed at the mainstream system? Do you really need four cores and a GPU crammed into a single chip and will it be cost-effective?"

The ISSCC conference runs through Thursday.

Andy Patrizio is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.