AMD - The Road Ahead

K10: What's in a name?

There's been this confusion over codenames when it comes to what we should call AMD's next-generation micro-architecture. Originally it was referred to by much of the press (and some of AMD) as K8L, and more recently AMD took the stance that K8L was made up by the press and that K10 is the actual name of its next-generation micro-architecture. Lately we've been calling it Barcelona, as that is the codename attached to the first incarnation of AMD's next-generation micro-architecture, destined for the server market. The desktop versions we've been calling Agena (quad-core), Kuma (dual core) and Agena FX for the Socket-1207 quad-core version, once again because those are the product specific codenames listed on AMD's roadmaps.

But when we talk about architecture, is Barcelona based on K8L, K10, or is there even a proper name for what we're talking about? To find out we went straight to the source, AMD's CTO Phil Hester, and asked him to settle the score. According to Hester, K10 was never used internally, despite some AMD representatives using it in reference to Barcelona. By the same measure, K8L does not refer to the micro-architecture behind Barcelona. It sounds like neither K8L nor K10 are correct when referring to AMD's next-generation architecture, so we'll have to continue to use Agena/Kuma/Barcelona in their place.

What happened after K8?

As we're talking about names, there was a project after the K8 that for various reasons wasn't called K9. Undoubtedly there was an internal name, but for now we'll just call it the first planned successor to the K8. The successor to the K8 was originally scrapped, but the question is how far into its development was AMD before the plug was pulled? According to Phil Hester, the project after K8 was in its concept phase when it was canceled - approximately 6 months of time were invested into the project.

So what was the reason for pulling the plug? Apparently the design was massively parallel, designed for heavily multithreaded applications. AMD overestimated the transition to multithreaded applications and made significant sacrifices to single threaded performance with this design. Just as the clock speed race resulted in Intel running straight into a power wall, AMD's massively multithreaded design also ran into power consumption issues. The chip would have tremendous power consumption, largely wasted, given its focus on highly parallel workloads.

The nail in the coffin of AMD's ill fated project was its support for FB-DIMMs. AMD quickly realized that Fully Buffered DIMM was not going to come down in cost quickly enough in the near term to tie its next microprocessor design to it. AMD eventually settled on unbuffered and registered DDR2 instead of FBD.

Without a doubt, AMD made the right decisions with scrapping this project, but it sounds like AMD lost about half a year doing the project. Given that the first K8 was introduced back in 2003, one canceled project doesn't explain why we're here in 2007 with no significant update to the K8's micro-architecture. We couldn't get a straight answer from AMD as to why Barcelona didn't come earlier, but there are a number of possibilities that we have to consider.

Barcelona is AMD's first native quad-core design, which is more complicated than simply sticking two independent dual core die on the same package. AMD committed the cardinal sin in microprocessor design by executing two very complicated transitions at the same time. Not only did AMD build its first native quad-core design with Barcelona, but it also made significant changes to the architecture of each of its cores.

Intel's Mooly Eden, the father of Centrino, once imparted some very important advice to us. He stated plainly that when designing a microprocessor you can change the architecture, or you can change the manufacturing process, but don't do both at the same time. AMD has already started its 65nm transition with its current generation parts, so the comparison isn't totally accurate, but the premise of Mooly's warning still applies: do too much at the same time and you will run into problems, usually resulting in delays.

There's also this idea that coming off of a significant technology lead, many within AMD were simply complacent and that contributed to a less hungry company as a whole. We're getting the impression that some major changes are happening within AMD, especially given its abysmal Q1 earnings results (losing $611M in a quarter tends to do that to a company). While AMD appeared to be in a state of shock after Intel's Core 2 launch last year, the boat has finally started to turn and the company that we'll see over the next 6 - 12 months should be quite different.