Using Power More Efficiently: Dynamic Tuning 2.0

A common thread in modern microprocessor design is being able to use the power budget available. There have been many articles devoted to how to define power budgets, thermal budgets, and what the mysterious ‘TDP’ (thermal design power) actually means in relation to power consumption. Intel broadly uses TDP and power consumption simultaneously, along with a few other values, such as power limits 1 and 2 (PL1 and PL2), which apply to sustained power draw and peak power draw respectively. Most Intel processors up until this point will allow a processor to turbo, up to a peak power draw of PL2 for a fixed time, before enforcing a PL1 sustained power draw. This is all very OEM dependent as well. However, for Ice Lake, this changes a bit.

For Ice Lake, Intel has a new feature called Dynamic Tuning 2.0, which implements a layer of machine learning on top of the standard turbo mode. The idea behind DT2.0 is that the processor can predict the type of workload that is incoming, say transcode, and adjust the power budget intelligently to give a longer turbo experience.

Technically the concepts of PL1 and PL2 don’t magically disappear under this new regime – the processor ends up going below max turbo because the algorithm predicts that the user won’t need it, and this saves up ‘power budget’ in order to enable the turbo to work for longer.

This is a topic that Intel will hopefully go into more detail. We do know that it requires collaboration at the OS level, but how these algorithms are trained would be a useful trove of information. It is unclear whether Intel will allow this feature to be enabled/disabled at the user level, for testing purposes, but it should be noted that unless it is by default ‘on’ for OEM systems, we might end up with some systems enabling it while others do not.

Two Versions of Ice Lake, Two Different Power Targets Thunderbolt 3: Now on the CPU*
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  • repoman27 - Tuesday, July 30, 2019 - link

    "It stands to reason then that the smaller package is for lower performance and low power options, despite being exactly the same silicon."

    I know the die floorplans are the same, but have Intel ever actually confirmed that U and Y (or H and S series for that matter) are the exact same silicon? Is it strictly binning and packaging that separates the platforms, or is there a slight tweak to the manufacturing process to target lower power / higher frequencies? Intel production roadmaps would seem to indicate this isn't just a binning situation, but I've never been entirely certain on that point.

    And isn't Comet Lake-U 6+2 more likely to be 25 W, with Whiskey Lake-U 4+2 continuing to pull 15 W duty alongside Ice Lake-U 4+2?
  • CaedenV - Tuesday, July 30, 2019 - link

    Those goals for Aethena are OK, but my old Dell XPS 12 with a carousel frame hit all of those except biometric, and wake from sleep in <1 sec... well, and the bezel... but that was due to the carousel design which I would LOVE to come back in a more modern form.
    Not saying these goals are bad... but if a 6 year old midrange laptop can hit almost all of them, then this isn't exactly aiming for something amazing.
  • AshlayW - Tuesday, July 30, 2019 - link

    Quad core for 179 USD? What is this, 2015? No thanks.
  • HStewart - Tuesday, July 30, 2019 - link

    You do realize these are ultra-portable low power cpu's and not desktop chips
  • Samus - Tuesday, July 30, 2019 - link

    Intel is a mess right now, the execution of this along with the naming scheme is ridiculous.
  • shabby - Tuesday, July 30, 2019 - link

    18% ipc gain and 20% clock loss
    Place your bets how intel will spin this.
  • CHADBOGA - Tuesday, July 30, 2019 - link

    I'm quite disappointed the issue of security mitigation in hardware was not addressed. o_O
  • CityBlue - Saturday, August 3, 2019 - link

    Disappointed, but not surprised.

    Security (and by inference the performance overhead required to implement proper security) is not important according to Anandtech/Ian Cutress. Which is obvious nonsense, so the only logical conclusion is that Anandtech are now a thoroughly biased outfit incapable of any critical reporting, which is quite sad particularly as it means all their articles (particularly when they relate to Intel) have to be read with a very heavy dose of cynicism.
  • eek2121 - Wednesday, July 31, 2019 - link

    That picture of you biting a wafer is priceless.
  • Santoval - Wednesday, July 31, 2019 - link

    If Ice Lake-U has a ~3.5% higher single core performance (and, assuming the "multi-core overhead" is the same, multi-core performance as well) than Whiskey Lake-U despite having a 20% lower single core boost clock, then Sunny Cove must be an extremely impressive μarch. Or, er, that might not actually be the case : Ice Lake-U has a 18% higher IPC than the *original* Skylake of 2015, not Whiskey Lake. While Whiskey Lake is basically the same design it must have a somewhat higher IPC due to its much more mature process node and other optimizations.

    Let's be conservative and assume that Ice Lake-U (more specifically Sunny Cove) has a nice round 15% higher IPC than Whiskey Lake-U, with both at 15W. In that case, at a 20% lower boost clock Ice Lake-U should have a 5% lower performance than Whiskey Lake-U. Where is that +3.5% performance derived from then?

    Even if we assumed that Ice Lake-U 18% IPC edge is over Whiskey Lake-U (highly unlikely, otherwise Intel would not have dug out the original Skylake from its computing grave) that would still translate to Ice Lake-U having a 1.5% lower single core performance than Whiskey Lake-U, rather than being 3.5% faster than it.

    Maybe, just maybe, this is why Intel used just a single synthetic benchmark (surely compiled with aggressive flags and optimized for Intel CPUs) for that graph and avoided to disclose other synthetic benchmarks and real world use benchmarks? Is this also why they avoided to talk about CPU performance of Ice Lake in their Computex presentation, and instead focused on iGPU, Wifi and AI performance?

    Based on the disclosed clocks and the "disclosed" (in obfuscated form) IPC of Ice Lake-U I just cannot see it being in any way faster than Whiskey Lake-U. It will probably also have worse power efficiency, since it has the same or higher TDP range at a much lower clock.

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