It took Intel 3 years to turn the tides of “war”, but those were 3 years well spent: the new Core microarchitecture that resulted was (and still is) quite excellent. Whilst we'll get into the juicy details hiding in the seas of silicon a tad bit later. At this point in time it should suffice to say that with its introduction, Intel had the best desktop CPU in all regards. It also had a good server proposition, which was important since it was in the server market where the greatest delta existed before. For multi-socket servers and for certain workloads, AMD retained something of an advantage due to some architectural traits of its CPUs, namely HyperTransport and the Integrated Memory Controller(IMC), but more on these later.

In case you're wondering what AMD was up to, the answer to that question is multi-faceted. Apparently they were doing little, introducing a number of mediocre tweaks to the K8 architecture, and giving the impression they were merely resting on their laurels. Less obvious to the outside world was the internal turmoil centered around bringing forth a new architecture. It's unclear just how things went on, but it is known that at least 2 architectures were considered, went into development and were subsequently scrapped. This involved wasted money and resources, and when your competitor outguns you in those areas significantly, such losses are seldom without consequence. Finally, the design of choice was the one we'd come to know as K8L/K10/Barcelona/Agena, which represented a natural evolution of K8 rather than a complete re-imagination of the successful chip.

AMD presented its new baby in 2006, but availability was planned for 2007 which gave Intel a rather serious head-start. However, going by what was disclosed and by the confidence shown by AMD officials, it appeared as if the K8L was going to mark a return to competition. What happened in practice was quite different from those early predictions.

Barcelona - beautiful city, awesome processor?

Late in 2007 AMD's much talked about new processor was finally released. Initially in its server-targeted Opteron incarnation, and subsequently as the desktop-oriented Phenom. To say that it was quite a flop would be something of a truism. Given the amount of hype that had been generated and the general expectations that had been established, partly based on overly-optimistic estimates by AMD representatives (“definitely in the double digits” rings a bell?), the K8L should've been the mother of all CPUs ever seen up to that date. Unfortunately for AMD it actually ended up being a rather troubled part that had significant issues with achieving satisfactory clock-speeds. Adding extreme insult to grievous injury, it also failed to achieve clock for clock performance parity with the competing Intel parts.

So, much lower clocks, lower clock-for-clock performance... could anything else go wrong? Actually, yes: AMD did a wonderful job FUD-ifying itself over an erratum involving the L3 TLB. Had a competitor attempted to create more Fear, Uncertainty or Doubt over the thing, it is doubtful it could've done a “better” job. Contradictory statements, apparent disorientation, and rather fatalistic reports helped amplify what would've normally been a moderately trivial thing into a completely show-stopping issue. When things were finally brought back under control the damage had already been done.

The 65nm Phenom drudged around (what else was there to do?), slowly ramping up clocks, getting a TLB-bug free B3 revision, and ending up near the end of its lifecycle in intense competition with the Core 2 Q6600... Intel's lowest end quad-core CPU. For servers things were slightly different since AMD's architecture had a number of advantages there, so it managed to be more competitive in the server space. Even still, the overall picture was not a rosy one.

The short history “lesson” above was meant to give an idea of where the 45 nm shrink of the K8L came in and what work was cut out for it. It had to fix the mess its older brother created, and had to bring at least some level of competitiveness back to AMD's offerings. Had it failed to do so, the company would've been relegated to a state of complete irrelevancy on the CPU market for at least the next 2-3 years. Which would've also more or less meant the near complete undermining of its status as a viable competitor to Intel. Throughout this article we'll try to see if those aims were reached. We'll also look at the K8L architecture and compare it with its competitors, try to grasp where AMD was coming from with its design choices, and hopefully provide you with an entertaining and detailed read.

With all that in mind, be aware that the first part detailing the architectures will be devoid of benchmarks, so if you're on the prowl for graphs and disinterested in silicon fueled yappings you'll have to absorb the next couple pages first.