I often work outdoors, and merely being in sunlight makes my 13” MBP go to max fan speed after about ten minutes, and insufferably slow after a half hour or so.

That doesn't strike me as particularly noteworthy/unexpected.

You don’t think it’s unreasonable that a laptop should work in daylight?

A 15" laptop's body could easily be absorbing 75 watts of heat from the sun, equivalent to running both the CPU and GPU of a MacBook Pro pegged at 100%.

I think throttling in this scenario is a reasonable tradeoff, much more so than overengineering the cooling solution to handle it and thereby increasing cost, weight and bulk. Sit in the shade.

Isn't the operating temperature of a mac laptop max out at something like 35c ? That's woefully low for anywhere it gets hot, like Australia for example. It basically means that on a hot day in summer you cannot use your laptop unless you're indoors in air conditioned comfort.

EDIT: Yes, I checked, the MacBook Air has an operating temperature of 10-35c and a storage temperature of -25-45c, which means that it's technically unusable or out of warranty if you use it in a hot country on a hot day. Like in the tropics on a beach for example.

I think you'll find that any device with a lithium ion battery will have similar temperature ratings if the manufacturer is being honest. Everything else in the machine is fine with much hotter temperatures, but cooking the battery is a bad idea.

The battery heat issue is especially problematic with LiPo cells, since they tend to swell up and break open the surrounding device enclosure.

35ºC == 95ºF - I'm at the upper end of that range sometimes, but not exceeding it.

I typically work from a hammock, in the shade, until it gets to 90-95ºF. The throttling happens even when the temperature is in the range of 80-85ºF and CPU load make it much worse. It's not uncommon for me to have to seek air conditioning if I'm running a large test suite or rebuilding docker containers, else my machine throttles to the point that I can't even use Safari.

I've never had this problem with any other laptop I've owned, including previous generations of MacBooks and MacBook Pros.

> like 35c

> you cannot use your laptop unless you're indoors in air conditioned comfort

Maybe it's just me being used to colder climate, but I feel that laptop's thermal throttling is going to be a relatively small issue if trying to work in sunlight when air temperature is +35C out there.

I'd really seek some shade even when it's merely +25C...

Not necessarily in the sun in that temperature, but just say indoors where there is no air conditioning. It's not bright sunlight but it can easily get to +35c. You yourself can cool down with a fan and a cold drink but the laptop is sitting around in hot temperatures in the shade.

"You're holding it wrong!"

Other laptops work in the sun.

I live on a beach in Thailand and it can get pretty hot at times. It is a beach in Thailand after all. I have no thermal issues with my Lenovo Yoga when sitting directly in the sun. Lots of MacBook Pro users around here and they do run in to thermal issues (random shutdowns mostly) if they sit in the sun doing something CPU intensive. Around here that would be using Ableton (music program), with up to 4 tracks loaded at the same time. We are blessed with amazing DJs around here and they all use a mac

My experience with various portable computing devices over the years is that they overheat and shutdown to protect themselves when used in direct sunlight combined with warm to hot ambient air temperatures.

I do not expect the manufacturers to overbuild the thermal capacity such that this isn't a problem, not when we're talking about portable devices which (appreciably) prioritize compactness and lightness.

In the past I would have to shade my laptop while using it to play MP3s from the passenger seat with the convertible top down while on road trips through Nevada, to prevent if from overheating in the direct sunlight. It never crossed my mind that this was some kind of failure on IBM's part, the machine was already pushing the limits of what was possible at the time in the interests of being small and light.

As a mechanical engineer, no. It’s basic heat transfer physics. You can’t throw money at the laws of thermodynamics and expect a physics bending solution.

I think it's unreasonable that a laptop should work at all -- knowing the myriads of components and software that makes it work and has all kinds of complexity.

As for the daylight, the sun is not the same as daylight. Devices have tolerances for heat, tropical heat in Miami is not the same as daylight in Chicago.

I'm in the middle - northern Arkansas.

To be clear, I don't make a habit of working in direct sunlight. Screen glare makes that impractical, even if the temperature warrants it. I do generally work from a hammock in the shade, and I deal with thermal issues constantly.

Even in the shade, at around 85ºF, I find that I start throttling noticeably when I run large test suites, recreate complex python environments, or build docker images. I keep a close eye on my system's sensor temps through iStat Menus, and try to tailor my laptop's workload around it. For example - I use Slack on my iPhone or iPad instead of on my laptop, and keep Safari closed unless I'm actively testing something in it.

Still, it seems like my machine throttles to uselessness right around noon. That's when my battery hits 20% or so unless I've been plugged in to my external battery, and about the time the temperature hits 85-90ºF.

In the summer I have to unplug one of my external monitors because my (maxed out) 2014 Macbook Pro gets too hot.

I'm going to try using my linux desktop when it happens next, that at least has adequate cooling.

Same here. 2014 maxed out, doesn't do well in the spanish summer. External screen mostly stays disconnected, otherwise it throttles down after 30 mins.. Are there not some kind of cooling pads to help with this shit?

I've had to do the same this summer in the UK. It's the first time we've had weather hot enough to trigger a problem, but it has been CRAWLING. :(

Same problem, I resorted to just have a fan blow on it to help with getting the heat away...

Do you have a way to monitor or measure the CPU throttling on macOS?

I've found Intel Power Gadget [1] which looks like it might help, however, I'm not really sure what these graphs should look like when throttling vs not.

[1]: https://software.intel.com/en-us/articles/intel-power-gadget...

Look up the specs for the processor in your system, then chart the temps alongside per-core clocks.

On Intel chips with a 1 to 4 core boost, no cores will rise above the base clock when thermally throttled, voltage may increase, and frequencies will be lower. You can run a CPU bound benchmark until temps rise and note when the performance begins to decrease.

On desktop Intel processors, this usually happens between 70-80°C.

That should work for revealing throttling -- you will see that it tops out at 1.1 GHz or something.

I have to run an accessory fan stand under my MBP.

But they’re so thin!

This is crazy. They have a metal body to use as a heat sink. Just put shielding on the parts that touch human skin and let the rest go toasty.

> Just put shielding on the parts that touch human skin

That’s literally the entire case. There is no part of a laptop designed to never touch human skin.