"7 Watt" Ivy Bridge my arse!

Discussion in 'CPUs and Overclocking' started by NTMBK, Jan 8, 2013.

  1. dastral

    dastral Member

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    Which leads to my suspicions about ""At 80° and Nominal speed, this chip will consume 7W"
    If that is correct, SDP is just a marketing ploy to impress the world with something we already knew...
    "Keep it cooler, and it will consume less"
     
  2. Exophase

    Exophase Diamond Member

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    Out of curiosity, do you have any numbers on the power needed to provide the extra cooling, assuming that you're running the desktop in a normal environment and not with its case open in an under heated house in the middle of winter?

    For instance, this tablet fan is 2W before any loss in the 5V regulator: http://www.laptop-cpu-fan.com/lenov...p-18477.html?gclid=CO27rZ_W27QCFe1xOgodnEUA7w
     
  3. Puppies04

    Puppies04 Diamond Member

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    A few years ago? Have you seen how much power a stock "125W" FX 8350 pulls?
     
  4. tweakboy

    tweakboy Diamond Member

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    Im guessing over 200 TDP ......... on a massive OC. 5Ghz all 8 cores.
     
    #104 tweakboy, Jan 9, 2013
    Last edited: Jan 9, 2013
  5. AtenRa

    AtenRa Lifer

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    TJmax = TAmp + (Rθja x Power)

    TAmp = Ambient Temperature
    Rθja = junction-to-ambient thermal resistance

    TAmp and Rθja should be constant in our case, we only have a change in the TJmax from 105c to 80c and Power from 10W to 7W.

    Now, it seams to me that SDP(Scenario Design Power) is something like AMDs ACP(Average CPU Power). So, if the CPU will not dissipate 10W or 13W and it only dissipate 7W because it will not be stressed up by the software to reach the Pmax allowed (10W or 13W) then the TJmax drops(in that case to 80c).

    So it has nothing to do with better/bigger Heat-sink or lower temperatures or no Turbo etc. It is just another TDP but, at 105c TJmax the TDP remains at 10W or 13W(depending of the CPU) and that is the design goal for the heat-sink.

    [​IMG]
     
    #105 AtenRa, Jan 9, 2013
    Last edited: Jan 9, 2013
  6. IntelUser2000

    IntelUser2000 Elite Member

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    SDP according to PCWatch:

    Additional level below cTDPdown that manufacturers can set. The limits are both Tjmax and clocks. They do say peak power usage is lower.

    So maybe I'm wrong about the Turbo thing but the basic premise is same. They cut peak clocks and lower temperatures to cut power.
     
    #106 IntelUser2000, Jan 9, 2013
    Last edited: Jan 9, 2013
  7. IntelUser2000

    IntelUser2000 Elite Member

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    cTDP: Configurable TDP
    http://www.anandtech.com/show/4764/ivy-bridge-configurable-tdp-detailed

    Manufacturers can set lower(cTDPdown) or higher(cTDPup) based on various scenarios. It's same as TDP.

    It's for Convertible Ultrabooks where you can use cTDPdown for say, in a Tablet environment, Nominal for Laptop, or cTDPup for docked or with a cooling pad.

    With TWICE the battery life and being thinner and lighter, I doubt most non-Anandtech consumers will care.
     
    #107 IntelUser2000, Jan 9, 2013
    Last edited: Jan 9, 2013
  8. Idontcare

    Idontcare Elite Member

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    It is definitely a numbers game which has no lower bounds to the absurdity with which it could descend.

    They could define SDP as the power used at 35°C and just require/expect OEM's to create magical water-cooling solutions that can keep the temperature at ambient + 7°C. Ridiculous to be sure but still technically feasible and possible.

    Likewise they could define the expected workload as being tantamount to running notepad or task manager. I.e. the idle power usage becomes "SDP" and it is marketed based on that. It would be absurd, but technically legit.

    I've unplugged the fans on my stock HSF and on my NH-D14 while the system was fully running and the power usage of those fans turned out to be tiny (~1W) but presumably we aren't talking about a 120mm fan to cool this 7W chip. Surely 7W could be effectively passively cooled with chasis-coupling or some such (turn entire tablet into a huge passive heatsink).
     
  9. Idontcare

    Idontcare Elite Member

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    You are absolutely correct, except you made the same minor mistake I kept making which is that you refer to the 80C value as a "TJmax" when what Intel is saying is that TJmax remains 105C, no change, but when the TJ is 80C then power usage can be expected to be 7W, etc.

    They are all points on the TJ curve, there is one TJmax (105C) and then a bunch of other points for power usage at a given TJ. Intel just picked (characterized) the power profile when TJ is 80C in these marketing slides and called that SDP for now.

    They could have picked TJ at 75C or 85C, the 80C value itself is purely arbitrary in terms of selection, but the 7W value is not arbitrary (it comes from characterizing power usage at a TJ of 80C).

    It is not that TJmax is now 80C, but that when TJ is 80C you have the power usage they are reporting. (note the footnote in the image)
     
  10. AtenRa

    AtenRa Lifer

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    @IDC,

    yeap my mistake, it is just TJ, TJmax is 105c
     
  11. Exophase

    Exophase Diamond Member

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    My question is, will it need more enhanced cooling than it would otherwise in order to decrease power consumption of the CPU. And basically, at what point is this investment worth the added power consumption of the enhanced cooling.

    Of course the total output of the tablet will be more than the CPU chip, also including the 3W PCH, a few W for RAM, and some consumption and efficiency loss in the PMIC. I don't know how much it helps having these components more spread out, but Haswell integrated VRMs counteracts this.

    I agree they won't use a 120mm fan, if they do need one it'll be smaller and AFAIK less efficient per amount of heat removed (but I don't know how fast it'll need to spin).

    So is the 7W what you get running the same processor load (frequency) and merely the savings yielded from lower temperature including the ability to use a lower voltage? Or are they merely saying that throttling it to 80C will also limit power consumption to 7W, but at a reduced load from what you can get at 105C/13W? Because that second part seems like a trivial claim, except to note that it CAN scale to 7W outside of idle states. This seems like the burning question to me, with different people on this thread claiming one or the other (ShintaiDX at least seems to be claiming the former)
     
    #111 Exophase, Jan 9, 2013
    Last edited: Jan 9, 2013
  12. Idontcare

    Idontcare Elite Member

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    Depends on what you are doing, obviously. It doesn't look like they are talking about superior binning, they are basically saying "look, if you can keep the temperature at 80C or below then the chip is gonna only use 7W or less, go above 80C and you are entering into 10W territory".

    So there are two ways to keep the temperature low - (1) improve the thermal conductivity and dissipation (see delidding the IB for example) or (2) use apps that are less demanding on the processor such that even when loaded the chip is not burning through the watts (stop using IBT people, stick with multi-threaded notepad as your most strenuous app).

    If you intend to keep the processor load the same (running same demanding apps), then obviously you need better cooling to get it below 80C if it otherwise operates above 80C when running the same app. If you configure the TDP to be the SDP then you are basically dialing down the effective CPU loading (TDP limit throttling) such that the processor is guaranteed to not exceed TJ of 80C when it hits SDP...performance suffers but it doesn't cost you any more because you can use the same crappy cooling solution.

    I have absolutely no clue as to the BOM expense structure these guys are looking at on their end. Its something I've never had the opportunity to be exposed to on the other side of the fence.

    I know with our desktop processors there is a very small window where replacing our stock HSF's with 3rd party coolers (at our own expense) reduces power consumption enough to justify the expense.

    Your 3rd party HSF needs to cost you less than $30 and it needs to lower your operating temps by roughly 20C if you have any hope of breaking even on your investment over the course of 2-3 yrs of operation.
     
  13. piesquared

    piesquared Golden Member

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    TWICE the battery life in what scenario? I haven't seen the review of that Vizio tablet, where did you see it? The only thing I saw was a stuttering mess on Clover Trail, of course that kind of performance might give slightly longer battery life. I think most people are going to want a tablet with a rich 1080p display that is useful, balanced and dominates gaming as opposed to an e-reader that can play lower quality movies. They might as well go to Barnes&Noble and pick up the latest top seller.

    [edit]
    Anyway, last post from me on this /off topic. This topic is about intel misleading consumers, not Clover Trail's bottom of the barrel performance. :p
     
    #113 piesquared, Jan 9, 2013
    Last edited: Jan 9, 2013
  14. Charles Kozierok

    Charles Kozierok Elite Member

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    This kind of puzzles me as well. Which comes first, the chicken (lower power) or the egg (lower temps)?
     
  15. Idontcare

    Idontcare Elite Member

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    It is both, of course, because you (the OEM) have the choice of which path you wish to pursue for your particular product.

    Design an aggressive cooling solution such that you are able to keep the temperature below 80C when it would have otherwise rocketed past 80C with a cheaper cooling solution and you will reap the benefit of then having a 7W footprint where others have a 10W product.

    Or...keep the same inexpensive cooling solution but set the cTDP to be equal to the SDP and the product will throttle itself (reducing performance but keeping power usage in check) such that it only uses 7W.

    Intel is saying "we aren't going to make the choice for you, you are free to choose which path you wish to pursue in creating the products you eventually want to bring to market and sell to your customers, but we are making both options available to you, either path will net you a 7W footprint, gl gg gb & gn"
     
  16. Hans de Vries

    Hans de Vries Member

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    Frankly I wouldn't even be surprised to see a 2014 3W Haswell smartphone
    demo setting a new world record in SunSpider below 200ms....

    With IVR's (integrated voltage regulators) you can in principle run Haswell with
    125W for a period of 200 ms from an ultra-capacitor in a phone.

    External power supplies show real power dissipation, but not anymore with IVR's.

    The 0.65W TDP Atom Z515 with up to 1.2 GHz and Intel Burst Performance
    technology requires an external 2.8W (1.1V 2.5A) power supply for instance
    which is 4.3 times the specified TDP:

    http://www.cpu-world.com/CPUs/Atom/Intel-Atom Z515 AC80566UC009DV.html
    http://www.intel.com/content/dam/ww...z520-z510-z500-45-nm-technology-datasheet.pdf

    and that's the TDP not even the SDP or whatever.


    Hans.
     
    #116 Hans de Vries, Jan 9, 2013
    Last edited: Jan 9, 2013
  17. TuxDave

    TuxDave Lifer

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    Very accurate summary, especially the first point of giving the OEMs to chance to get a competitive advantage through cooling innovations. Although I guess it's debatable whether Intel openly gave the OEMs the choice or was it the OEMs demanding that Intel give them that choice. :D
     
  18. sm625

    sm625 Diamond Member

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    This begs the question, why does surface pro have a fan? Why not just limit it to 7W so it doesnt need a fan? And why does 2012 ivy bridge still require a 3 watt PCH anyway? The whole topic is moot so long as this remains true. You've got 3 watts in the PCH and probably another 3 watts lost in the power supplies, another 2 watts in memory/NAND and 3 in the display. So even if the cpu is limited to 7 watts, you're still burning through 18 watts, or looking at 2~2.5 hours battery life under load. And then there's wifi/cellular on top of all that? Ugh. This is miserable any way you slice it.
     
  19. Charles Kozierok

    Charles Kozierok Elite Member

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    Okay, sure, they have a choice. But didn't they always? :)
     
  20. Olikan

    Olikan Golden Member

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    that remembers me that ivy's HD 4000 would be 3 times faster... than in a very small font saying: against HD-2000

    not a lie, but it is a really cheap move :\

    this remembers me that... haswell igp might be 5 times faster than HD-2500 :thumbsdown:
     
  21. ShintaiDK

    ShintaiDK Lifer

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    The Surface Pro uses a regular 17W product as far as I know.

    Its the combined savings that matters. Display makers, memory makers etc also pursue the same. 21W vs 18W is still almost a 15% difference for example.
     
  22. Idontcare

    Idontcare Elite Member

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    For the "implement better cooling to get lower power usage at same performance" option, yes, that option has always been there.

    But they didn't have the option to set the max TDP to any number within a range of values (that is what cTDP brings to the table) nor did they have the option of being guaranteed by Intel that if they keep temperature below a specific value (80C in this case) then they can formally spec (and advertise as such) the product as being a "7W Processor" which is a big deal for OEMs selling to resellers and retailers.

    This is about legitimizing in the business sense what was available to the hobbyist in the past. Turbo-boost/core was one step in that direction, adding the performance tuning plan was another (OEMs can now sell pre-OC'ed rigs that are legitimately covered under warranty), and configurable TDP is yet another step in that same direction of legitimizing a product segment so that it can then be monetized and brought from the fringe and into the mainstream (where the volumes are to be found).
     
  23. Haserath

    Haserath Senior member

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    The surface pro has a fan because it's just that cool.:cool:
     
  24. Haserath

    Haserath Senior member

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    One thing that gets me is why don't we have a tweak able laptop yet... I'd love to boost battery life and reduce heat with some voltage tuning.
     
  25. Exophase

    Exophase Diamond Member

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    So you're saying that better cooling alone will decrease power consumption for the same workload.

    But then you said you don't know what workload actually measures, that it could be anything. If what you're saying is true then it's whatever the same workload 10W cTDP is. Now I have no idea what that represents, but cTDP isn't really new so maybe there's some information out there. I expect Intel should still be able to run the CPU cores at its base clock at least, under "normal" programs that fully load it (ie not doing weird power virusy things). And with the GPU only doing minimal GUI stuff.

    The problem is that nowhere do I see that Intel is clearly describing this. Maybe to you it's implied by the slide, but I think there's still some room for ambiguity. 10W to 7W is a huge reduction just from 25 degrees C at TJ, which I imagine is nowhere close to saying a 25C reduction in ambient; the temperature of the cooling elements on the tablet are going to be nowhere close to 25C over the air around you.

    The savings should be less dramatic if already starting at lower voltage levels, especially given that Intel's 22nm voltage/clock curve rises more steeply than on its older processors. For your graph you have things fixed at a high 1.29V which I'm sure exaggerates the results.