Tuning Cool'n'Quiet: Maximize Power And Performance, Part 2

Benchmark Results: DivX And WMV, No Hardware Acceleration

This scenario will likely apply to many of us watching video on our PCs without hardware-accelerated video. It’s a bit more interesting to look at because, with this scenario, we will be able to see power consumption when the processor is fully loaded.

Interestingly, DivX uses fewer resources for playback than WMV. A multi-thread codec is able to spread the task more evenly between available cores. In effect, this means having more cores (in lower p-states) leads to more savings than having fewer cores (in intermediary p-states). Compare the DivX and WMV graphs. With WMV, all processors are unable to use lower p-states (and thus unable to save power) compared to DivX.

That doesn’t mean DivX is not resource-intensive. Just look at the Athlon X2 7750 and Phenom II X3 710. These processor lack the performance to play our DivX test video clip while in their lowest p-states, forcing them to use the higher/highest p-state. You can keep this from happening by customizing the multiplier used by the lower/lowest p-states as demonstrated in Part 1.

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  • Anonymous
    I would have liked to see how the quad 810 processor would have gone, considering it is just one peg above the triple core 720, and a few pegs below the 945 and 955 - perhaps it yields a nice balance/performance/voltage ratio? Certainly interesting given that it is a 95w processor, but possessing four cores, I guess that it would have trumped the 720. Maybe AMD sponsors these articles, and have to sell a few more 720s first.
  • chispas
    AMD 810 FTW
  • silverblue
    I doubt AMD sponsors these. Have you seen how poorly the 710 does at DivX? I doubt that DivX will change their code for triple core CPUs, so the 720 will behave similarly to the 710. In addition, this guide is an AMD-only guide.