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Comment by izacus | Hacker News Reader

Every MacBook Pro I've ever owned locked it self down to low frequency after running a CPU intensive task for a minute or so.

I thought that was common knowledge? There's NO laptops out there that wouldn't do that (and NO mobile devices either). This is why desktop workstations are still so much faster even though they carry same frequency chips.

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What makes you think this? Lots of laptops have severe throttling issues and the thin-and-light trend of the last few years has not really helped the situation but there are certainly laptops out there that have adequate cooling systems and do not thermally throttle. I was kind of shocked when I got the original Thinkpad X1C (14" screen and weighs 3lb) that it maintained 100% boost clock with no throttling over the entire span of hours-long video encoding workloads.

Take the Intel's CPU frequency tool, run compilation on your MacBook and see how the clock gets locked to < 2GHz (exact frequency dependent on CPU you have) after the CPU temperature reaches a barrier (usually around 80C).

I don't have a Macbook? I have a Thinkpad that remains at 100% of the 2.6Ghz max turbo clock indefinitely at ~60C because it has a good cooling solution.

Notebookcheck reviewed the i7 version which is clocked higher than mine. Max boost is 3Ghz and in their tests it maintains 2.8Ghz running Prime95, drops to 2Ghz while running simultaneous CPU and GPU stress tests.

https://www.notebookcheck.net/Review-Lenovo-ThinkPad-X1-Carb...

Sure, but the amount of throttling his tested configuration was running at was fairly significant.

Most laptops can at least run their base clock most of the time, his MacBook couldn't even do that (2.2 GHz vs 2.9ghz). The XPS 15 is considered a PC laptop with subpar thermals and even those issues only crop up during turbo, not baseclock (same CPU).

I've been doing hours-long CPU+GPU intensive tasks (compiling ghc, number crunching, playing games like Bioshock Infinite and StarCraft II on a HD4000) on a bunch of pre-retina MBP and rMBP 13" and they never throttled. Thermal design and management is spot on, fans stay silent most of the time and kick in only when load requires it.

Beware of anecdata. Given the stories I hear I would squarely put the various issues in the realm of thermal paste gone bad, busted fans, or clogged airducts, and certainly not on intrinsic bad design because I have personal counterexamples of dozens of various Apple laptops from 2008 to 2016 being perfectly fine out of the box.

Obviously though, a desktop will beat a laptop's thermal performance any day but I think this is missing the point.

> I've been doing hours-long CPU+GPU intensive tasks (compiling ghc, number crunching, playing games like Bioshock Infinite and StarCraft II on a HD4000) on a bunch of pre-retina MBP and rMBP 13" and they never throttled.

I find that hard to believe. I have been gaming a lot on MacBook Pro unibodies and retinas with and without an external GPUs. Especially when the internal GPU is active, the thermal load is just too high for many games and applications.

Throttling normally starts in a very subtle way by disabling clock boost and is hard to notice. Throttling below the base clock is rare and this is where it becomes really noticeable.

I thought that was the one of the points of turbo boost? To take advantage of high clock frequencies for short high intensity hurts while still running at the base clock for long term work? If the clock speed is staying above the base clock I wouldn’t consider it a problem.

It isn't throttling if it is operating at or above base clock.

My data comes directly from monitoring the CPU frequencies as I was doing development work. There's an intel tool that gives you that data in realtime.

I did mostly only have the 15" MBPs, but thermal throttling is a fact of life on pretty much all mobile devices. I do mobile development work and having mobile CPUs run at full frequency for more than a minute or two is pretty much impossible.

>There's NO laptops out there that wouldn't do that (and NO mobile devices either).

My 10 years old HP nc6400 doesn't do that. It requires occasional (once a year) cleaning of the fan assembly though (not that hard to access). The fan is loud, the laptop is bulky but it never ever throttles. The CPU has 34W TDP, I do not think that's on the low side.

I've only ever had issues with 5yo+ laptops, and that's due to thermal paste degredation. I wouldn't pay for a laptop if it thermal throttles. I'll forgive the passive cooling on my phone for not keeping up with the CPU, but if the fans on a laptop are running full power and the chip thermal throttles why should I even consider buying it?

Keep in mind, there's a difference between thermal throttling and low boost clocks on multi-core workloads.

That, and also battery life (and the extrapolated time left until empty) takes a severe hit when doing CPU intensive task for more than a minute.

Does anyone know if thermal throttling is so much of an issue for iPads?

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