How Dell cripple performance explained by Notebookcheck.net

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Papusan, Sep 14, 2017.

  1. Papusan

    Papusan BGABOOKS = That sucks!! STAHP! Dont buy FILTH...

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    How Dell cripple performance - explained by Notebookcheck.net
    You're all welcome:hi: FYI, Frank Azor @Alienware-Frank is also VP General Manager for the DELL - XPS lineup. Not only for the Alienware lineup.
    upload_2017-9-15_6-38-33.png
    @Mr. Fox @j95 @TBoneSan @unclewebb @Rage Set @Johnksss@iBUYPOWER @tilleroftheearth @Ashtrix @Phoenix @ajc9988 @Falkentyne @0lok @Vasudev @Mobius 1 @Cass-Olé @hmscott @Donald@HIDevolution @bloodhawk @thattechgirl_viv @aaronne @Prema @syscrusher @Huniken @Jon Webb @Coolane @ole!!! @Arrrrbol @ThatOldGuy @UsmanKhan @bennyg @Tanner@XoticPC @cj_miranda23 @ssj92 @D2 Ultima @Stress Tech @leftsenseless @thegh0sts @Georgel +++ All not mentioned but not forgotten.

    "Using a combination of hardware and software, Dell designs its XPS lineup of notebooks to dynamically adjust power inputs to the various components to ensure that the system operates within specified temperature limits. We explain how Dell implements its Dynamic Power Policy to maximize performance within design constraints."

    Why enforcing power limits is essential
    "CPUs that are power-efficient operate within the specified thermal limits and, therefore, consume a lesser quantity of power. If these CPUs were to be pushed for more performance, there needs to be a mechanism to dissipate the excess heat produced. One way of doing it is to implement a heatsink, which can absorb and dissipate excess heat away from the CPU.
    Sometimes, due to design constraints(Crippled), <it is not possible to design huge heatsinks> — but it is still essential to keep the CPU performing at its peak. Under such conditions, enforcing a low power limit (Aka cripple the product) will ensure that the heat dissipated is within the required range."

    How Dell's Dynamic Power Mode helps
    "Each notebook has its own design and has to be individually optimized for maximum performance while remaining within the skin temperature limits. Instead of just setting functions based on worst-case thermal limits, power limits to electronic components can be dynamically adjusted based on temperature feedback from thermal sensors placed at specific locations in the system. Correlation between skin temperature readings, power draw, operating frequency, device temperature, and other factors are established that enable the Dell Dynamic Power Mode to predict the surface temperature. This results in a matrix of power limits and thermal rules that are applied in real-time to adjust power limits to various components. This is implemented via a combination of Embedded Controller (EC) connected to each component and OS-based controls. The Intel Dynamic Platform Thermal Framework (DPTF-Aka Cancer software) provides a software framework for Dell's power policies."

    Dell Dynamic Power Policy: A look into how Dell manages thermal and power policies across its XPS lineup
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    Dell implements its Dynamic Power Policy across the entire XPS lineup (Source: Dell)
    Using a combination of hardware and software, Dell designs its XPS lineup of notebooks to dynamically adjust power inputs to the various components to ensure that the system operates within specified temperature limits. We explain how Dell implements its Dynamic Power Policy to maximize performance within design constraints.
    by Vaidyanathan Subramaniam, 2017/09/10
    Business Gaming Kaby Lake Notebook Software Windows XPS Working For Notebookcheck

    Introduction
    Notebooks are getting more powerful by the day and manufacturers are leaving no stone unturned to ensure that premium notebooks perform as close as possible to their desktop counterparts. However, unlike desktops, notebooks have limitations on how much power can be crammed into a portable chassis while also considering other factors like mobility, thickness, etc. Due to the limited space for heat dissipation, there is a cap on performance of individual components, primarily the CPU and GPU. To ensure these components exude maximum performance while still keeping temperatures in check, OEMs come up with various measures to meet a certain performance threshold even under heavy load. They achieve this by means of a combination of hardware sensors and software algorithms that constantly monitor system load and change the power inputs accordingly. The Dell XPS 13, XPS 15, and XPS 13 2-in-1 have special sensors built-in that gather real-time temperature info from strategic locations in the notebook. Here, we discuss how Dell achieves performance compliance under load by implementing Dynamic Power Mode in their premium XPS lineup.

    Why enforcing power limits is essential
    Power is required to drive all electronic components in the notebook. CPUs and GPUs are silicon-based and operate by means of a clock frequency, i.e. the number of instructions that can be executed per second. The clock frequency at which an electronic component such as the CPU, operates is determined by a lot of factors, but the most notable of them is the power input. The higher the power consumed, the higher the clocks, and consequently, the faster the computer. High power consumption also means high heat production.

    CPUs that are power-efficient operate within the specified thermal limits and, therefore, consume a lesser quantity of power. If these CPUs were to be pushed for more performance, there needs to be a mechanism to dissipate the excess heat produced. One way of doing it is to implement a heatsink, which can absorb and dissipate excess heat away from the CPU. Sometimes, due to design constraints, it is not possible to design huge heatsinks — but it is still essential to keep the CPU performing at its peak. Under such conditions, enforcing a low power limit will ensure that the heat dissipated is within the required range.

    Generally, CPUs and GPUs are rated for a certain power limit value called the thermal design point (TDP). The chip manufacturer guarantees that the chips will operate at designated frequencies within the limits of the specified TDP value (provided adequate cooling is ensured) so that the chip does not cross something called the thermal junction temperature or TjMax. Operating within the specified values is adequate for nominal performance, but notebook OEMs constantly look towards extracting the maximum possible performance from the silicon while still innovating on slimming down the overall dimensions of the notebook. Even if the heatsink is large, there occurs a point beyond which the effectiveness of the heatsink in slowing temperature increase, falls. This point is called the "thermal soak", which is a saturation point for the heatsink. The thermal soak should be reduced by removing the soaked up heat by means of a fan. During this process of heat absorption and dissipation by the heatsink, there will be periods of high power draw for high performance and periods of low power draw for low performance.

    The periods of high power draw cannot be sustained long enough as it will lead to increase in temperatures beyond the specified thermal limits and will consequently soak the heatsink for a longer time. The hotter a chip gets, the less efficient it is with power. To deliver maximum performance in this short window, CPUs and GPUs boost the clocks to perform an intensive activity and return back to nominal or idle state as soon as the activity is completed. This allows the chips to cool and gives the heatsink-fan combo enough time to dissipate the soaked up heat.

    How Dell's Dynamic Power Mode helps
    As discussed earlier, notebooks have a size constraint. They need to be as thin as possible while still being able to perform at their peak. As each notebook generation gets thinner than the previous, the vicinity of the operating surface gets very close to the heatsink-CPU assembly. Due to the absorptive nature of the heatsink, this area can be extremely hot and make working with the notebook a huge safety concern. Although chip manufacturers set thermal limits and guarantee optimal performance within these limits, in the interest of operational safety, CPUs, GPUs, and any other high performance components must not be allowed to reach these thresholds.

    Each notebook has its own design and has to be individually optimized for maximum performance while remaining within the skin temperature limits. Instead of just setting functions based on worst-case thermal limits, power limits to electronic components can be dynamically adjusted based on temperature feedback from thermal sensors placed at specific locations in the system. Correlation between skin temperature readings, power draw, operating frequency, device temperature, and other factors are established that enable the Dell Dynamic Power Mode to predict the surface temperature. This results in a matrix of power limits and thermal rules that are applied in real-time to adjust power limits to various components. This is implemented via a combination of Embedded Controller (EC) connected to each component and OS-based controls. The Intel Dynamic Platform Thermal Framework (DPTF) provides a software framework for Dell's power policies.

    The Dynamic Power Mode Policy can therefore, adapt to the notebook's usage. If the system is docked, the policy can set a higher temperature limit. Similarly, if the system is hand-held or worn, the policy can set a lower limit in real-time. Thus, maximum performance within the dynamically adjusted power limit can be provided.

    Dell offers the following explanation with respect to how power is dynamically adjusted —

    The thermal and power policy dynamically adjusts power to allow performance to be maximized within the constraints of the mechanical design - i.e. the thermal capacitance of the heatsink and conductivity through the specific material stack-up unique to each platform. By monitoring these values in real-time and using them as inputs to the models constructed in a controlled series of laboratory experiments, the system will adapt to the user's environment as well as their particular set of applications and how those apps load (lightly or heavily) the components within the system."



    Conclusion
    With a combination of hardware, software and firmware, Dell's Dynamic Power Policy aims to extract the maximum possible performance from the XPS lineup by dynamically adjusting power levels based on input from thermal sensors. Power management will be all the more essential for upcoming notebooks featuring the 8th generation Intel Kaby Lake-R ULV chips (15W-25W TDP) since they are in many ways chips that previously required a 45 W TDP. We look forward to review Dell's upcoming refreshed XPS lineup using the 8th generation Intel CPUs and evaluate how Dell's implementation of Dynamic Power Policy lets them stack up to the competition.
     
    Last edited: Sep 15, 2017
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  2. Cass-Olé

    Cass-Olé Notebook Consultant

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    FazorBlades are never a good thing Poppy. As you know, I've done the deep dive into Snailienware desktops for years now; as I put on my preferred public persona as a concern troll (Cass-Trollé) my main concern right now is their (starting at) $3000 Threadripper 1950x desktop, who uTubers TimmyJoe, Jayz & others have reported that their standard 140 x 280mil AIO liquid coolers are worthless for overclocking that new chip (Enermax 360 is the cure of course), & so as a way to get a post started on your crippled thread here, I'll drop a photo of the AlienTechnologies 120 x 48 kooler, then make a simple observation: if a 280mil cooler can't cope with heat inside of purpose built dream-machines with ample fans at all 4 corners (7-10 fans at times), we expect Fazor to put his thumb on the scale to take control of this pre-built desktop's over-clocking (in)ability in order to combat (reduce) massive heat whilst using an undersized cooler, the bare-minimum cooler, the weak link in that overpriced system --> through Alien Crippled Power Policy

    If Jailienware doesn't blush in locking down a high-cost desktop, they never will when it comes to their line of BGAware / XPOS disposables. Frank, well, he was the 3rd employee on staff, the janitor / stockboy; now self-stylized as a 'co-founder', mmmhmmm. When Linus told the world their TRipper overheats with mild overclocking, Frank said: 'no it doesn't! You're a bad reviewer! Don't believe Linus!'. Mmmhmmm, must suck living in a world of digital goodness & traveling the world over, yet having to peddle Mr Dell's junk for a living. I wouldn't work there if he paid me
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    This website is a chore lately, IE11 hates this place > long-running scripts, page reloads, crashes, agh
    edit:
    Old habits die hard :eek: I found / fixed the problem: ScriptingDictionary was disabled, pages here run ok now
     
    Last edited: Sep 23, 2017
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  3. Mobius 1

    Mobius 1 thwink

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    why are you using IE11?
     
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  4. j95

    j95 Notebook Deity

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    AW 3 + QA tetraphobia, not really...
     
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  5. Assembler

    Assembler Notebook Consultant

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    So true.. :vbbiggrin:
     
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  6. tijo

    tijo Sacred Blame Super Moderator

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    If you ask me, the problem stems from their "design constraints". I am ok with the thin and light designs making some kind of compromise on component TDP to fit your design's thermal envelope. This however is not the kind of design compromise you make on a high performance system. Pick the performance you want and then design the chassis + thermal envelope accordingly, don't try too cram something that will run to hot in an existing design and then cripple it with some wonky power management. I have my doubts that Dell management was willing to invest the cash necessary to do good get good power management models and algorithms.

    What isn't fine though is that their dynamic thermal management kicks in in scenarios like gaming, etc. If you're running Prime95 + Furmark simultaneously, then sure, you're putting the system under the most stress it could be under an unrealistic extreme scenario and a little bit of thermal throttling would be fine on a given component, as long as you're capable of dictating whether you want the CPU or GPU to be affected.

    What really scares me is this:

    You can fit correlations to pretty much anything and your correlation may not mean anything. The fact that they mention correlations rather than modeling has me scared. A simplified, but with a sound physical basis heat transfer model is likelier to yield better overall thermal management than any random correlation. They also just listed a bunch of variables and a good multivariate analysis is not simple and so on.

    Once you've got your model, again make the design according to component TDP, add a safety factor to it (very often simplified heat transfer models tend to overestimate rather than the other way around). That way, you know that power management shouldn't kick in under use unless there is something wrong like failing thermal paste, dust buildups, etc.

    In the end, it almost sounds like manglement told their engineers and designers to do something unreleastic, which the engineers and designers likely told them was not realistic. Manglement being manglement didn't listen, engineers did their best with what they had and then manglement put some PR on top of it...

    Places where I see that kind of power management shining is on battery power top increase runtime or to keep the notebook running silent. That is fine as long as there is user control over it.
     
  7. Papusan

    Papusan BGABOOKS = That sucks!! STAHP! Dont buy FILTH...

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    Is this advanced system intelligence technology for the new Alienware's same as explained so well in this thread? Most likely.

    Alienware 17 R4 Review, New Era of Gaming - haghgostar.com

    "Alienware has its own system intelligence, which includes your attention, in front of the laptop, it can automatically optimize power usage and especially trigger advanced security profiles, which is a groundbreaking feature in Alienware machines."

    upload_2017-9-28_2-43-41.png
     
    Last edited: Sep 27, 2017
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  8. Mr. Fox

    Mr. Fox Undefiled BGA-Hating Elitist

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    You should be scared. There is every reason to be. The problem is (and I know this from the relationships I had with them) skin temps is like their golden calf to which literally everything is a secondary concern. There is no wiggle room on that spec based on their company policy, so performance ends up taking a back seat as a matter of necessity. They cannot deliver full performance and still hit that target. The thinner they make them for the sake of popularity, the more performance has to be compromised to meet that skin temp drop-dead goal. Clock speeds have to be lowered, throttling becomes a means to that end, watts have to be lowered, the system has to use less power, etc. or it will not be compliant with this arbitrary threshold that someone decided needed to be the most important consideration for a Dell/Alienware notebook. This is really unfortunate, as it stifles what they are able to deliver just because of that one measurement. Since thin is popular with the Facebook generation, I don't see this problem going away... ever. It will likely only get worse.

    They have had that spec for a long time. It used to not matter that much because end users that don't give a rat's butt about skin temps were free to override things and get full performance. We didn't care about skin temps. What's different now is they no longer allow Alienware owner's to make their own decisions and castrate their junk with firmware and hardware gimping techniques.

    What is so ironic is that this nonsense flies in the face of the stupid engineering stunts we see them pulling with uncooled components like MOSFETs and crappy designs like the tripod heat sink and fake radiators. Maybe if they paid closer attention to the small things they could eek out a little more mojo from their turdbooks and not have to be so OCD about things like skin temps.
     
    Last edited: Sep 29, 2017
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  9. ralba

    ralba Newbie

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    I really like Dell laptops but this is my main concern, they have good support, nice products and design but software and bios implementing it's just awful, after 1 year that the 7567 was out on the market, last month they fixed the HDMI performance bug (intel driver) when using the laptop with lid closed and connected to an external monitor.
     
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  10. John Ratsey

    John Ratsey Moderately inquisitive Super Moderator

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    But how many other manufacturers would never fix the bug at all?

    John
     
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