AMD Phenom - A Second Try with the B3 Stepping

What a sobering year it’s been for AMD. Its ray of hope, the Phenom processor with its four CPU cores, dynamic speed and power management and shared L3 cache, was not only released far too late, it also nearly became a flop despite its outstanding architecture. For one thing, AMD is still unable to ship CPUs running at more than 2.4 GHz. Also, the CPU maker had to completely halt shipments of Opteron processors based on the same core, since a bug in the translation lookaside buffer (TLB, also known as Erratum 298) for the L3 cache could cause data corruption under some circumstances. While this isn’t overly critical for home users, such an error or even the risk of it occurring are completely unacceptable in the business segment – and proved to be nothing short of a fiasco for AMD.

Now various rumours about a possible bug in the Phenom’s third core are making the rounds on the internet. This topic has motivated many heated and very detailed discussions on message boards and forums around the web, including ours. It seems like a plausible explanation for AMD’s dilemma and would also explain AMD’s plans to begin shipping tri-core Phenoms in the very near future. AMD curtly dismissed these rumours as completely unfounded. On the other hand, we weren’t able to reproduce the reported problems either, so maybe this is not just the company’s attempt at damage control. In the end, the cause doesn’t really matter that much anymore as far as we’re concerned – what AMD needs to do is fix the problem, pronto.

Apparently, AMD’s fix seems only a few days away. We just received a new Phenom CPU whose launch is still a few weeks away with only minimal advance notice. According to our tests, this CPU is based on the highly anticipated B3 stepping that users are apparently expecting to be something of a small miracle. It is meant to be error-free, allow higher clock speeds and still consume less power than the Phenom 9300 and 9400 models (2.2 GHz and 2.3 GHz, respectively) released last November. At any rate, the new CPU worked without a hitch in the test system we used a few weeks back to compare the energy efficiency of various AMD processors ranging from the Sempron and the Athlon 64 X2 to the Phenom.