Over the last few days we’ve seen outcry about Apple’s new MacBook Pro, which offers an optional top-end i9 processor, and how its performance is throttled to the point of parody as the laptop heats up over time.
Sparked by a video from YouTuber Dave Lee, who demonstrates that the only way to get Apple’s quoted performance from the MacBook Pro is by keeping it in a refrigerator, the outcry has been brutal.
Thousands of comments on the video say things like “Wow if it cant even maintain stock speeds that's pretty sad” and “Apple should offer a fridge that goes with the Macbook i9,” but the sobering reality is that this practice is normal across laptops—we’re just starting to see it more often.
As our expectations have shifted for how we get work done with computers, it’s become popular to try and foist even the most demanding workloads—like video rendering, software development, and high-end gaming, on laptops. It’s been a fun shift to be a part of, and the things you can do with a laptop now are wild: VR on the go, or rendering motion graphics on a train, but for day-to-day, the shift has messed with our perception of what ‘performance’ means.
Desktop computers faded in popularity over the last decade, but many of the tasks we’re demanding from our laptops simply can’t compete with the raw power of a desktop in the physical constraints of their form factors. The problem, almost always, comes back to heat: there’s too much of it, and not enough space to get rid of it.
The shift away from desktop computers and toward laptops can be blamed on enterprises, and the ‘bring your own device’ movement, which was designed to save money. Instead of needing to provide a computer on every desk for employees, the employer could provide a laptop that can be used on the go as well—or even require you to bring your own hardware. At VICE Media, for example, most employees are given Apple laptops.
The company saves money, and your desk gets a docking station, so you feel happy knowing you can use that comfy, familiar device. But the tradeoff is that even a high-end laptop is going to struggle to compete with the specifications of reasonable desktop computer.
The pursuit of thinner, lighter laptops, a trend driven by Apple, coinciding with laptops replacing desktops as our primary devices means we have screwed ourselves out of performance—and it's not going to get better anytime soon.
What’s going on?
Thermal throttling is not something that Apple alone suffers from: every laptop out there will face thermal constraints at some point, but whether or not that’s perceivable depends on a number of different variables including form factor and cooling capacity.
When you’re shopping for a laptop, you’ll notice that manufacturers like Apple use phrases like “Turbo Boost” and “Up to 4.8 GHz” without really explaining what that means. The 4.8 GHz processor clock speed, which Apple quotes for the 15-inch MacBook Pro, is a ‘best case’ processor speed that’s only achieved in short bursts when your computer requests it, subject to a number of conditions.
If you’re playing a game like Fortnite, for example, the game will request your processor provide faster performance, and the processor will attempt to increase its operating frequency gradually to deliver the maximum available performance within the thermal envelope of your machine.
That maximum is restricted by both power and thermal limits, which is where we run into issues: laptops tend to get hot because they’re thinner, with limited space to dissipate that heat through the use of fans and heatsinks.
The temperature limits and when throttling kicks in vary between chipsets, but Intel refers to this threshold as the “TCC Activation Temperature.” These settings cannot be changed and are hidden from the user for a reason: they’re confusing, and the big numbers provided by Turbo Boost sound better if you leave this out. Intel’s detailed specifications in ARK, which cover everything from the size of the CPU to the maximum temperature it can reach, intentionally exclude this metric.
Depending on what type of laptop you own, this metric can be different. With a tool like HWInfo for Windows, you can see where TCC Activation kicks in: on most laptops, this is a sustained 80-90 degrees Celsius over a longer period of time. It can also be much lower, however, meaning that your machine slows down sooner as it gets hotter.
MacBook Pro owners can use a free tool to monitor and deduce this called Intel Power Gadget. Linus Tech Tips used the tool to discover the device throttling at around 90 degrees, just 20 minutes after coming out of the box. This probably won’t happen when you’re browsing the web, but if you put the machine under load for even a short amount of time, you’ll likely hit this ceiling too.
Thermal throttling is a normal practice in the laptop industry, but it's difficult to understand because of Intel’s smoke-and-mirrors marketing that obfuscates the real clock speed of a processor behind larger numbers like ‘turbo boost’ or “quad core.” 4.2GHz sounds fast, and surely is better than 4.0GHz, but when you’re throttled all the time that won’t mean much, let alone the fact that the processor only ‘boosts’ to that speed some of the time.
From the user's perspective, throttling usually feels like this: at first your machine will be incredibly fast, but the longer you spend doing your work, the higher the temperature goes. Once the machine reaches a sustained temperature that breaches TCASE, the laptop will silently start throttling, and games might struggle to maintain a frame rate, or workloads like video rendering will take longer.
This, by the way, is the reason that gaming laptops look huge half of the time: they’re enormous to accommodate more cooling hardware than anything else. Even so-called ‘thin and light’ gaming laptops are absolute units, because performance-focused hardware requires as much airflow as possible.
The pursuit of thin
Apple’s insatiable thirst for thinner, which we can see across the iPhone and Mac, appears to have finally caught up with the company. Its new hardware is the most powerful yet, but the form factor betrays that on-paper performance, because the laptop’s form factor means it’s thermally constrained.
The iFixIt teardown of the 2018 MacBook Pro, above, reveals the problem: every inch of this machine is full of hardware, which competes with the fans and miniaturized heatsink that’s layered at the top edge of the machine to cool it. While this amount of cooling is adequate for most workloads, professional tools such as Blender 3D or XCode will quickly find the thermal ceiling, and performance will suffer.
Outside of making the MacBook thicker—which is unheard of, for Apple—there’s little the company can do to solve this. This isn’t the only thermally constrained machine Apple builds, either. After years of silence, Apple admitted in 2017 that the top-end Mac Pro was stagnant because “[…] we designed ourselves into a bit of a thermal corner, if you will.”
On thicker laptops in the same weight/performance class as the 2018 MacBook, such as the Dell XPS 15, thermal dissipation is a little better due to more available chassis space—but even that machine eventually suffers from similar throttling woes.
Because the new MacBook is so thin, there’s simply nowhere for that heat to go, and there’s few ways to increase the heat dissipation of the fans—as a result the temperature climbs faster as heat can’t be pushed out.
Some enterprising laptop owners use tools like ThrottleStop to undervolt the CPU, which allows users to lower the voltage of the CPU, reducing heat and potentially squeezing extra performance out of these machines. Doing so, however, isn’t the point: you and I don’t have time for that, and these constraints should be known before purchasing.
The problem isn’t throttling
While the laptop industry's marketing practices surely need a shake up to make these realities clearer for the user, that isn’t really the core problem: the ‘pro’ industry’s expectations are. From developers to videographers, we’re all forcing increasingly demanding workflows on smaller, thinner laptops every year, when we should be using desktop computers instead. These people are a loud minority, with specific needs, and I don’t think they’ll ever be satisfied.
Desktop computers have fallen out of fashion as consumers moved toward tablets and smartphones, and it got more annoying than ever to keep multiple machines in sync. It almost seems absurd to have a giant box under your desk to get work done, because you’ve got a supercomputer in your pocket, so why can’t a laptop do the same? For Windows and Linux users, you can just build your own PC if you need raw power, which is reasonably cheap. macOS fans, however, are left at Apple’s mercy.
Apple’s sell, however, isn’t oriented toward those people anymore: its laptops are all-in-one packages designed for the masses, not the pro user. That we’re still even using them is a side effect of its success, and the quality of the Mac brand, when the reality is that they aren’t always the best machine for the job.
This hurts Apple’s most demanding users more than anyone else, because they’re basically left without options as a result of the limited Mac desktop lineup. In the absence of the forthcoming Mac Pro refresh, the only high-end option that won’t suffer from throttling available to users is an iMac Pro, which comes with a high price tag.
There’s another way, however: larger laptops.
If Pro users really were Apple’s target market, the company could redesign these laptops to use the older, thicker MacBook Pro form factor from 2015. With that available space, and improvements in processor design, it would be able to better cool the same hardware and squeeze out more performance—but it’ll never happen. Thicker laptops would mean admitting failure.
Thinner and lighter is great, and if we’re honest, we’re all sucked in by the allure. The unfortunate reality for those of us that need these machines for work is that it’s just not good enough, and we’d welcome thicker machines in exchange for hardware that isn’t constrained by heat. Apple insists these new MacBooks are for ‘pro users,’ and while it has some of the best-in-class hardware design out there today, it simply doesn’t hold up if you push them hard enough.
The MacBook Pro isn’t designed for pro users at all, it’s a slick marketing machine designed to sell to the wealthy ‘prosumer’ that wouldn’t notice anyway. That much has been clear since the introduction of the Touch Bar and death of the SD slot—and it’s making a ton of money anyway.