AMD's Next-Generation Mobile Architecture Revealed: Griffin

Several years ago Intel discovered surprisingly enough that its NetBurst architecture was not very good for the mobile space.  As wonderful as the idea of battery powered space heaters was, Intel quickly discovered that to build the perfect mobile platform you had to start from scratch and design a CPU that was built for the mobile space.  By doing so Intel could make tradeoffs that it wouldn't normally make, performance for power reduction, many of which we diagrammed in our first Centrino articles.

Intel also discovered the power of the platform; by bundling a good CPU with a good chipset and wireless controller, three independent Intel products were transformed into a marketing powerhouse.  The Centrino brand simplified notebook purchasing and quickly became a mark associated with a notebook you wanted to buy.

It took AMD a bit longer to get on the bandwagon, putting marketing first and worrying about architecture last.  We had heard rumors of a mobile-specific AMD microarchitecture, but nothing ever surfaced until now.  AMD's design team out of Massachusetts worked on the project, and today we're finally able to tell you about it.  The processor is called Griffin, and the platform is called Puma, both are codenames; AMD will undoubtedly come up with a phenomenal name for the final product (sorry we couldn't resist).

When Intel started development on the first Centrino processor, Banias, it had to go back to the P6 for a starting point.  The Pentium 4's NetBurst architecture was hardly suitable and the design team was intimately familiar with the P6 core at the time.  The end product hardly resembled a P6 and if you look at what the architecture evolved into today, you would be hard pressed to say it was similar at all to a Pentium III. 

AMD didn't make the misstep of a Pentium 4, it made a solid evolutionary step to K8 from K7.  Griffin's execution core and underlying architecture is based on the current generation 65nm K8 design, not Barcelona/Phenom.  You can take everything you are looking forward to being in Phenom and throw it out the window, as AMD is starting from the same K8 core that launched in 2003.

By no means is it a bad starting point, but thankfully AMD did toss in some enhancements.  Griffin gets a new North Bridge, a new memory controller, a power optimized Hyper Transport 3 interface and a 1MB L2 cache per core.  Griffin will still be built on a 65nm process as AMD will have, at best, only begun its 45nm production by the time Griffin debuts. 

Right off the bat you see a disparity between AMD's approach and Intel's approach; while the K8 is arguably a better starting point for a mobile-specific architecture than the P6, the K8 was heavily designed for servers and scaled down.  But as we've seen, the K8 is quite power efficient, with 35W TDPs easy achievable for dual core versions, so the race isn't over before it has started.

Griffin will go into production at the end of this year, and AMD is targeting availability in the first half to middle of 2008.  Given the launch timeframe, much like Phenom, AMD won't be competing with today's Core 2 processors but rather tomorrow's Penryn based notebooks.  Penryn does have some mobile-specific power improvements that even Griffin does not, but the opposite is also true as you will soon see.  AMD quoted a maximum TDP of 35W for dual core Griffin CPUs.  AMD hopes that notebooks based on Griffin can offer beyond 5 hours of battery life, but do keep in mind that battery life will vary greatly based on OEM implementation.