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The World's First 65 W Desktop Quad Core


As far as performance is concerned, AMD is lagging behind its competitor Intel. But few users other than gamers still care solely about performance. In this age of burgeoning energy prices, AMD has an ace up its sleeve: the world’s first quad core CPU that consumes as little as 65 W (TDP). In comparison, Intel’s smallest quad core absorbs 95 W (TDP), despite the fact that Intel is already using 45 nm technology and AMD is still at 65 nm.

In terms of power consumption, AMD’s platform as a whole — motherboard, CPU and graphics chip — is not bad either. Its performance is perfectly adequate for office work and entertainment, though not for games. The integrated graphics engine in the 780G chipset is capable of rendering Blu-ray movies in 1920 HD resolution under maximum CPU load without jitter via HDMI. With Intel, this is only possible with a separate graphics card, as a comparable platform is not yet available.

AMD still has difficulties with high clock frequencies. While Intel’s quad core easily touches the 3 GHz mark, AMD is barely capable of 2.5 GHz. The Phenom X4 9100e presented in this article operates at 1.8 GHz.

Compared to classic Athlon 64 X2 CPUs, the first Phenom models with the B2 stepping featured improved power efficiency, but due to a TLB error — largely irrelevant in practice — the maximum clock rate had to be limited to 2.30 GHz. The B3 stepping eliminated the error, allowing the clock rate to be pushed up to 2.50 GHz. As even the B3 update failed to provide a major boost to the clock rate of the Phenom core, AMD was forced to increase the core voltage. Thus, the Phenom X4 with the B3 stepping is characterized by an extremely high power consumption (TDP) of 125 W.

Nevertheless, Tom’s hardware test of Phenom X3 CPUs provides evidence that AMD is capable of reducing the Phenom’s power consumption by optimizing the production process. Using a core based on the B3 stepping, the voltage and current requirements are much lower compared to the quad-core models at the same clock rate.

The following sections will shed light on how AMD was able to set the bar at 65 W.