Truly Independent Power Planes

While architecturally Griffin is no different than today's Athlon X2s, it will draw noticeably less power in normal use.  AMD is the first to announce the next step in multi-core power management: independent voltages and frequencies for each core.  While Phenom splits the North Bridge and CPU cores into two separate voltage planes, Griffin goes one step further and puts each individual CPU core onto an independent voltage plane.  The benefit is that not only can each core run at its own frequency, but it can also run at lower voltages giving you significant reductions in power consumption.

Dynamic power of a CPU can be determined by the following equation:

Power = ∝ * C * V^2 * F

Simply reducing the frequency of a processor (F) will result in a linear reduction in power consumption, but as you can see voltage (V) has an exponential relationship to power.  Reducing both is ideal, and that's exactly what Griffin does. 

Each core can run at one of 8 frequency steps and five voltage levels, independently of one another.  Deep and deeper sleep states are supported, however AMD is currently looking into the possibility of implementing a C6 sleep state similar to what Intel announced for mobile Penryn.  AMD wouldn't commit to whether or not we'd see a C6 state in Griffin, leading us to believe that it simply wasn't implemented at the time of Intel's Penryn announcements and there may not be enough time to add it in before launch.

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  • Goty - Friday, May 18, 2007 - link

    I agree with your points here, but it might have come down to an issue of time and manpower. Intel probably has teams of engineers sitting around twiddling their thumbs just waiting for something to do while AMD probably has everyone working around the clock. It's probably more a result of resources than anything. Reply
  • TA152H - Friday, May 18, 2007 - link


    I think you're right, but a product like that could make a big difference too. It would be so different than anything out there, and have such advantages for the market it is designed for, I think it is something they should have looked at.

    I guess what's so disappointing for me is they mentioned that they were going to try a completely new design for it, and then they just did another iteration of the K8 and took a branch from there. I don't think they can seriously differentiate themselves from the Core 2 line, and I think they have to. Intel is so much better in manufacturing, if AMD retains design parity, or something close, I don't know how they are going to be successful. I think Fusion is a good idea, but I don't think it's enough and I don't think it would be hard for Intel to duplicate, because as you say, they have the resources.

    Besides, they have the K6, they'd have to increase the memory interface, improve the decoders, and tweak little things here and there, but it's a great processor. Remember how disappointed everyone was when the K7 couldn't beat it clock normalized for integer and it was beating the Katmais that were 50 MHz faster? This with the putrid VIA MVP3 chipset that had horrible memory performance. It was a really good design.

    I am also wondering why they still have such strong x87 in the Athlons. Why even bother these days, particularly with the mobile part. Put in a tiny non-pipelined version for compatibility, and save the space for something more useful. x87 isn't even supported in x86-64 mode, so it's clearly a dead technology.
  • LoneWolf15 - Friday, May 18, 2007 - link


    The Centrino brand simplified notebook purchasing and quickly became a mark associated with a notebook you wanted to buy.

    Maybe it did for Joe Sixpack, but it ticks me off. Centrino tells me nothing about what kind of processor is in a system, it just tells me that the system has a wireless card (of some sort, Intel branded but who-knows-which-model). Centrino could mean Pentium-M (Banias or Dothan), Celeron-M, or Core Solo. Centrino Duo at least tells me a system is dual-core, but not whether it's Core Duo or Core 2 Duo (or possibly "Pentium Dual Core", that relabeled Core Duo Intel is putting out in limited quantities). You call this simple? I sure don't.

    I can't stand this marketing trend. There is very little way to "at-a--glance", know exactly what you are getting in a given laptop. It's just one more buzzword to know, when just saying the laptop has WiFi (which 95% do at this point) and an Intel xxx processor running at such-an-such a speed would be useful. And it looks like it gets review sites like Anandtech sucked into buzzword bingo in the process.
  • IntelUser2000 - Friday, May 18, 2007 - link


    Centrino could mean Pentium-M (Banias or Dothan), Celeron-M, or Core Solo. Centrino Duo at least tells me a system is dual-core, but not whether it's Core Duo or Core 2 Duo (or possibly "Pentium Dual Core", that relabeled Core Duo Intel is putting out in limited quantities). You call this simple? I sure don't.

    Actually, Celeron M based laptops can't be certified as Centrino. Here is the chart from Intel:">

    And you can further differentiate the single core Centrinos from the dual cores. Dual core versions are Centrino Duo, and single core ones are Centrino. It looks like even the logo can be different for Core Solo compared to Pentium M.
  • acejj26 - Friday, May 18, 2007 - link

    power consumption is linear with respect to frequency and quadratic with respect to voltage, not exponential Reply
  • elpresidente2075 - Friday, May 18, 2007 - link

    You do know that they are one in the same in this instance, right? Reply
  • Goty - Friday, May 18, 2007 - link

    x^2 is quadratic, a^x is exponential (a being some constant).

    Big difference.
  • JarredWalton - Friday, May 18, 2007 - link

    a^x is indeed exponential... and yet, x could be something like... 2! :) Reply
  • Seer - Friday, May 18, 2007 - link

    The OP is right and you're completely wrong. I came on here to post the very same message.

    The definition of x in this case is that it is a variable. If both x and a were'd just have a single number. There would be no relationship. Go back to Algebra I if you truly don't understand this.
  • goku - Friday, May 18, 2007 - link

    Seeing innovations like this where they're doing more with less just really makes me happy. It's nice to see that they're addressing power concerns and working towards having a powerful computer that also can be power conservative.

    While the hardware industry is getting more efficent, unfortunately the software industry is following the trend of the P4. Software is getting more and more inefficient and bloated while hardware is getting more efficient. It'd be nice if this trend would reverse and would start seeing better software written again..

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