Updated: Tuning C'n'Q: 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.

  • nzprogamer
    GO AMD go
    i am telling you my next build AMD/ATI
    """I WILL BE BACK"""
    Reply
  • jedimasterben
    I'd be interested to see the tests performed on Windows 7 to see what the effect of reducing thread "jumping" would be.
    Reply
  • cnox
    Dammit...how can this part 2 article be posted before the Building the Balanced PC Part 2?

    Cumon....
    Reply
  • melangex3
    Great Stuff. Keep up the good work. This is the type of review that will keep me coming back. How about throwing in the ever popular 720 BE and the new 620 or 630 just for giggles?
    Reply
  • Ryun
    jedimasterbenI'd be interested to see the tests performed on Windows 7 to see what the effect of reducing thread "jumping" would be.
    I was thinking the same thing as well.

    Also, were the BIOSs all updated? The asynchronous clocks problem you're experiencing with Athlon II X2 was supposed to be fixed with updated CPU microcode.
    Reply
  • Summer Leigh Castle
    620 and 720? :D
    Reply
  • redgarl
    I must admit that lately AMD is impressive. I got a PII X3 720 BE unleashed at PII X4 20 fully stable with an Asus M4A78T-E latest BIOS. Let simply add that my 2 radeon 4850 OC in Crossfire are running as fast as 2 stock 4870...

    If you take into account that the 2 cards only cost 82$ each for a total of 165$ for the two... I can hardly believe that so little money can give so much results.
    Reply
  • JimmiG
    With my Phenom X4 9650, I found Cool n Quiet to be pretty much worthless without tweaks. There were huge performance drops across the board, especially with tasks that didn't use all four cores, or only loaded cores partially. Videos and games would stutter and skip every couple of frames, compressing files would take longer etc. I basically had a 1.1 GHz CPU that would sometimes run at 2.3 GHz, if it felt like it. Too bad there was no tweak guide available then. I just disabled CnQ which solved all problems but made the system use more power and run hotter.

    With my 955BE, I haven't really had a need to tweak CnQ. It might cause a slight performance hit in some rare cases, but generally when I need a 3.2 GHz CPU, that's what it delivers.
    Reply
  • tacoslave
    Nice, amd owns in the graphics department now with that $1.2 billion im sure amd is heading to pwn BOTH markets.
    Reply
  • saint19
    Good!!!, I have my 955 to 3.8GHz at 1.5V....
    Reply