Thermal Throttling Cripples Apple's Macbook Pros Using New Core i9

The thermal solution inside Apple’s newest professional laptops may not be up to the task of keeping the fastest processor running up to spec.

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When configuring a new top-of-the-line Macbook Pro on Apple’s website, you’ll have the option to include Intel’s 2.9GHz six-core Core i9 CPU for an additional $300. Before you complete that transaction, you should know that early reports from users claim that the laptop is unable to keep the Core i9 within its thermal limits, resulting in performance throttling when the laptop is under a heavy load. The issue was first brought to light by Youtuber David Lee in a video he made about the new 15-inch Macbook Pro with the Core i9. The findings from that video have also been corroborated by other tech outlets since the video was first posted.

Modern CPUs automatically adjust their speeds based on a few factors, most importantly by the power required of a computing workload and by the thermal limits of the CPU itself. The Intel CPU in question is sold as a 2.9GHz six-core solution. When presented with a heavy load (and with proper cooling), the CPU can automatically boost one (or more) of its cores up to 4.8GHz. The wide range of operating speeds allows mobile (and desktop) users to have access to cutting-edge processing power while controlling power use to prolong battery life. This is especially important for laptop users.

Due to their size, laptops are known to make tradeoffs in performance to make gains in power efficiency and temperatures. The Core i9 CPU that comes in some of the new Macbook Pros has a default clock speed of 2.9GHz while its desktop counterpart is sold as a 3.7GHz part. Most desktop PCs have the space to accommodate better cooling designs, while laptops must get by with less space and smaller fans. The design of the Macbook Pro cooling system is just over two years old now and is simply not up to the task of dealing with a big, power-hungry chip like the Core i9.

Testing from David Lee (as well as AppleInsider) show that under a heavy workload from Adobe Premiere, the Core i9 in the new Macbook Pro is operating anywhere from 2.3 - 2.65GHz, under the rated 2.9GHz speed and a far cry from the advertised TurboBoost speeds of 4.8GHz. AppleInsider found that the Macbook Pro with the Core i9 was unable to complete the rendering task any faster than a comparable Apple laptop with the slower Core i7 CPU. While keeping the Core i9 cool is a challenge for all laptop makers, tests done on other manufacturer’s units do not show the same CPU operating under the baseline spec.

As of this writing, Apple has yet to address the issue. While many are blaming the company for pairing such a hot CPU with an inadequate thermal solution, others are pointing the blame at Intel for its failure to deliver faster, more efficient CPUs on its originally promised production schedule. In the meantime, if you are in the market for a top-of-the-line Macbook Pro, you may want to consider avoiding the Core i9 option until Apple offers a software solution or a change to the Macbook Pros cooling design.

Contributing Tech Editor

Chris Jarrard likes playing games, crankin' tunes, and looking for fights on obscure online message boards. He understands that breakfast food is the only true food. Don't @ him.

From The Chatty
  • reply
    July 23, 2018 10:55 AM

    Chris Jarrard posted a new article, Thermal Throttling Cripples Apple's Macbook Pros Using New Core i9

    • reply
      July 23, 2018 11:07 AM

      Thanks Stovr

    • reply
      July 23, 2018 11:09 AM

      Why Stove Jabs, whyyyyyyyyyyy

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      July 23, 2018 11:10 AM

      This is the kind of thing that leads to bait-and-switch and false advertising lawsuits.

    • reply
      July 23, 2018 11:39 AM

      Not sure how anyone can blame Intel for this with a straight face. It's Apple's job to design the computer around the parts they use, not the parts manufacturers to design the parts around Apple's computer.

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        July 23, 2018 11:41 AM

        ^^^ This. And Apple has a long, long history of designing things around style rather than functionality.

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        July 23, 2018 12:24 PM

        Intel didn't hit the 10nm production it promised Apple 2 years ago. Which has been obvious for at least a year. That's the crux of the argument I heard.

        I'm convinced there are no Computer Science people left at Apple

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          July 23, 2018 12:32 PM

          It's Apple's job to cope with that, either by reengineering the laptop, or by delaying until Intel can meet their claimed production.

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            July 23, 2018 12:34 PM

            They could have "delayed" by releasing an i7 line with a decent keyboard and had all my money.

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            July 23, 2018 1:45 PM

            Apple's designs are beautiful and functional. It's just another antennagate, where their design philosophies bit back.

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            July 23, 2018 3:09 PM

            They delayed 32GB of RAM until Intel's chipsets could manage it better and everyone told them they didn't care about pros.

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              July 23, 2018 3:46 PM

              The larger battery is why we're seeing 32GB since LPDDR4 never happened. The new models are a bust either way, at least until Cannon Lake hits.

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        July 23, 2018 1:54 PM

        Apple fans think Apple can do no wrong so it must be Intel's fault.

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      July 23, 2018 12:48 PM

      MKBHD, TLDToday, and a few other reputable Youtube folks are seeing noticeable performance improvements with video rendering on their i9s vs the older generation's i7s even on longer renders, so not sure what's going on there.

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      July 23, 2018 1:14 PM

      Anyone considering buying one of the new Macbook Pros should seriously consider this. It appears Apple will no longer be able to recover data if the logic board fails, since the SSD is soldered to the board.
      https://www.macrumors.com/2018/07/22/2018-macbook-pro-lacks-data-recovery-port/

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        July 23, 2018 1:42 PM

        I’m not sure what the news here is, they’ve been soldering the SSD chips to the boards for years now. In fact it doesn’t really have an SSD per se, it’s got chips that store data but not a removable drive.

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          July 23, 2018 1:44 PM

          The change is that they removed the port that let them use a separate toll to recover data. Did you read the article I linked?

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            July 23, 2018 2:48 PM

            With the inclusion of the T2 and hardware encryption on by default, it would't matter if you did have the port because the drive's data would not be recoverable without the T2 functional (i.e. the drive is AES encrypted against a hardware bound identifier in the secure enclave.

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            July 23, 2018 3:08 PM

            The effect of which is mitigated if you just do backups, preferably using he Time Machine mechansim built into the computer.

            I suspect the reason is both the T2 chip singlespace mentioned as well as basically wanting to be out of the business of being capable of retrieving information for law enforcement.

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        July 23, 2018 3:39 PM

        Anyone who relied on that is a fool anyway.

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        July 23, 2018 4:11 PM

        I would not rely on that as a recovery method in the first place.

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        July 23, 2018 4:16 PM

        That's not a reason to consider anything. Back your shit up.

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      July 23, 2018 4:25 PM

      As a engineer that does alot of thermal design, though not electronics, we are the last design concern of the project at times it seems. We are not as interesting as say a piece of turbo machinery or an obvious profit center like chemical process design.

      Sigh...