Finally, with a little help from Anand's article, we were able to shed some light on some of the erratic performance numbers that have made our Phenom benchmarking life miserable from the beginning. We might actually have figured out some of what is going on... and share it!

Speedbumps and Typical Design Power

Speed bumps are not always the most exciting thing to write about. Aren’t they usually just the official validation of something that most overclockers have achieved months ago? Give or take a few, that seems fairly accurate but, in contrast to the casual or die hard overclocker who does not really care whether the system crashes once in a blue moon, an official specification of any given speed requires 100% stable operation of the system under the most averse conditions – otherwise it won’t work.

This said, there is a bit more to the story: Higher frequencies are most often achieved by increased voltage, and, as written in numerous textbooks, power consumption increases with the square of the voltage. Add a bit of higher junction temperature as a result, and the power consumption will increase a bit more. Some additional leakage current will do the rest to inflate the overall power profile of the CPU – not a good thing in a world turning greener by the minute.

Phenom X4 9350e and X4 9950

The next question in that respect concerns the infrastructure of the motherboards and the on-board voltage regulator modules. It doesn’t require insider information to realize that the single most important aspect in the Far East computer industry is the red pen, a tenth of a penny savings on a few components on every motherboard result in pretty substantial savings by the end of the year. Needless to say that the power supply easily falls victim to these measures and that is where minimum requirements by the processor manufacturers become the sole barrier against going back to the dark ages of single phase VRMs with a few bulging capacitors.

Now, in case anyone is not aware of this, these minimum specifications are what is called Typical Design Power or short: TDP. In other words, any CPU with a given TDP requires that number of power to be supported by the motherboard, otherwise, there will be no qualification of the motherboard for that specific CPU. In theory (and certainly also in practice) the TDP will also take into account whether the model at hand is a darling of the overclocking community, an unlocked edition will most likely have a higher TDP than a locked-down version that will never reach the Nirvana by flying high above its more pedestrian brethren.

It is important to understand the difference between a platform requirement and a real energy efficiency rating as the role of the TDP, strictly speaking, it is the first and not the latter. In other words, any CPU can in theory be fit into any TDP rating, the only things that need to be changed are the voltages and the clock frequency. Of course, it helps if the CPU is energy-efficient by design, otherwise, the frequency would need to be, well, think about a 500 MHz Smithfield, for example.

Aside from energy efficiency, the high end of any CPU line is important for any company. Regardless of whether the bread and butter SKUs are competitive or not, the high end usually takes the top on the performance charts. In that respect, AMD’s promise of a 2.6 GHz model – as anticipated with the never released Phenom 9900 - has never materialized. Until now, that is.

What we have today is the introduction of AMD’s so far fastest Phenom, model name X4 9950 and two low energy CPUs dubbed X4 9350e and X4 9150e running at 2 and 1.8GHz with a NB at 1.8 and 1.6GHz, respectively. Outside of the OEM channel, HT frequency (which cannot be higher than the NB frequency) of 1.6 GHz is not yet supported, and so we skip that particular model and concentrate on the X4 9350 along with the X4 9850. Upcoming revisions of 780G and the new 790GX chipset (not yet launched) will have multipliers for 1.6GHz HT 3.0.and nVidia is following suit.

In an interesting marketing gig, AMD is waiting for another week and will slash prices for the current top model, that is, the X4 9850 to just above $200.- on July7, while maintaining it’s unlocked Black Edition status for … maybe another 6-8 weeks. A golden window of opportunity? In the final analysis, it’s up to the user to decide, we just provide some information ...