Intel's Kaby Lake Branding Confounds, But The Real Devil Is In The TDP Details

All the king's horses and all the king's men cannot fix the trouble Intel has gotten itself into with the fractured re-branding effort behind its 7th-gen Core (Kaby Lake) processors. The new branding scheme is somewhat confusing because it discards the previous "m7" and "m5" nomenclature for Intel's low-power SKUs and brands them as "i5" and "i7" parts.

This will surely confuse shoppers, but the disappointing news is that the muddy branding waters hide a deeper undercurrent of obfuscation. OEMs can restrict Kaby Lake TDPs, which adjusts performance, into lower settings that extend below the advertised 4.5W and 15W power ranges. By the same token, Intel also allows vendors to adjust the TDP settings to exceed the normal specifications, which means there is an equal (though less likely) chance that the processors will feature higher-than-normal specs.

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Paul Alcorn
Editor-in-Chief

Paul Alcorn is the Editor-in-Chief for Tom's Hardware US. He also writes news and reviews on CPUs, storage, and enterprise hardware.

  • turkey3_scratch
    Here come the threads, "How come my games start to lag when I pick up my laptop?"
    Reply
  • BadActor
    I'd really like to see how the HD 615 and 620 graphics perform in games with the...ahem, i7.
    Reply
  • turkey3_scratch
    What I don't understand are Intel's tricks to making the TDP so low. We have the I7-7500U. 2.7Ghz turboes to 3.5Ghz. Then we have the desktop Pentium G4400 3.3Ghz with a 54W TDP. Seems like a large gap to me. Then again their TDP numbers are sometimes inaccurate I think.
    Reply
  • mavikt
    This sounds like great news for hardware review sites! Busy busy...
    Reply
  • Discorama
    Turbo frequencies are pushed pretty high. Too bad most of the devices these CPUs will be used in will throttle down due to heat and never use them.
    But yeah, really comes down to how well the 615/620 perform as that is always Intel's weakness.
    Reply
  • jimmysmitty
    18533742 said:
    What I don't understand are Intel's tricks to making the TDP so low. We have the I7-7500U. 2.7Ghz turboes to 3.5Ghz. Then we have the desktop Pentium G4400 3.3Ghz with a 54W TDP. Seems like a large gap to me. Then again their TDP numbers are sometimes inaccurate I think.

    Why are you comparing a low power laptop chip to a desktop chip?

    Intels TDP is normally the max power a CPU can dissipate before it throttles. For the i7-7500U it is a low power part so it has limitations put in place to keep it from hitting higher power numbers.

    One benefit the i7 has is a more mature process. One example is the i7 4770K and i7 4790K:

    http://ark.intel.com/compare/80807,75123

    The i7 4790K had a 4w TDP disadvantage but a 500MHz clock speed advantage and clocked higher in overclocking. A more mature process tech and tweaks can help the TDP of a CPU.
    Reply
  • turkey3_scratch
    18533927 said:
    18533742 said:
    What I don't understand are Intel's tricks to making the TDP so low. We have the I7-7500U. 2.7Ghz turboes to 3.5Ghz. Then we have the desktop Pentium G4400 3.3Ghz with a 54W TDP. Seems like a large gap to me. Then again their TDP numbers are sometimes inaccurate I think.

    Why are you comparing a low power laptop chip to a desktop chip?

    Intels TDP is normally the max power a CPU can dissipate before it throttles. For the i7-7500U it is a low power part so it has limitations put in place to keep it from hitting higher power numbers.

    One benefit the i7 has is a more mature process. One example is the i7 4770K and i7 4790K:

    http://ark.intel.com/compare/80807,75123

    The i7 4790K had a 4w TDP disadvantage but a 500MHz clock speed advantage and clocked higher in overclocking. A more mature process tech and tweaks can help the TDP of a CPU.

    I was just wondering, if you have a laptop and desktop chip of the same architecture. Let's say they have the same number of cores and threads. Let's say same frequency. Does the laptop part still perform worse and cooler for any reason other than less cache?
    Reply
  • TJ Hooker
    18534004 said:
    18533927 said:
    18533742 said:
    What I don't understand are Intel's tricks to making the TDP so low. We have the I7-7500U. 2.7Ghz turboes to 3.5Ghz. Then we have the desktop Pentium G4400 3.3Ghz with a 54W TDP. Seems like a large gap to me. Then again their TDP numbers are sometimes inaccurate I think.

    Why are you comparing a low power laptop chip to a desktop chip?

    Intels TDP is normally the max power a CPU can dissipate before it throttles. For the i7-7500U it is a low power part so it has limitations put in place to keep it from hitting higher power numbers.

    One benefit the i7 has is a more mature process. One example is the i7 4770K and i7 4790K:

    http://ark.intel.com/compare/80807,75123

    The i7 4790K had a 4w TDP disadvantage but a 500MHz clock speed advantage and clocked higher in overclocking. A more mature process tech and tweaks can help the TDP of a CPU.

    I was just wondering, if you have a laptop and desktop chip of the same architecture. Let's say they have the same number of cores and threads. Let's say same frequency. Does the laptop part still perform worse and cooler for any reason other than less cache?
    An educated guess:
    1) Unlike desktop parts, mobile parts (especially -U and -Y) are typically only expected to be able to reach maximum boost clocks for short periods before throttling. This is why a low power mobile CPU may perform worse than a desktop chip with all the same specs (including boost clock).
    2) I believe mobile parts are binned for low power consumption (i.e. low leakage) which, combined with 1), explain why they can have lower power consumption than a desktop part with seemingly equal specs.

    Also, like you said, TDP isn't really an accurate measure of power consumption. It's actual purpose is to designate the general level of performance (i.e. heat dissipation capability) a heatsink would need to cool that part. The fact that a i5 6600 and 6400 have identical TDP shows that it's not exact. If I were to speculate, maybe Intel really dials in the rated TDP on their mobile parts because of how constrained cooling/power is on the kinds of systems that would use those chips, whereas with desktop they just ballpark it (and overestimate for the sake of erring on the side of caution), because it's not as important. Like I said though, this is just my own thoughts on the matter.
    Reply
  • Matthew_157
    Think about this for a sec: "there is an equal (though less likely) chance"
    Reply
  • bit_user
    Good reporting, Paul.

    The new branding makes it a whole lot harder for the average user to determine just what Intel is inside (as it were)
    Oh... Snap!

    I'm not too worried about manufacturers permanently down-clocking a more expensive part, because it would cost them more than buying a cheaper SKU and overclocking it.

    My guess is that people are going to spend a lot of time looking at graphs of clock speeds, but that's already the case, for mobile.
    Reply