> Fully parallelized workloads in a consumer laptop are just exceedingly rare.
Eh? Probably THE most common workload for a laptop (opening a webpage) is multi-threaded. And even consumers multi-task. As soon as you have multiple processes, you can use multiple cores even without multi-threading support.
> Plus it's exceedingly pointless to do lengthy multi-threaded development on a laptop, it's going to overheat and under-clock.
The promise of these laptops is that they won't. As you say, their power consumption is a lot lower than competing chips, and it's that power that produces the heat.
> If I had to guess they know what they're doing engineering wise, but they're taking a calculated (and poorly thought out, in my opinion) risk that a small percent of people will regularly peg the cpu at 100% usage, and they're further relying upon clock rate throttling and the cpu die thermal sensor to keep things from melting down.
If that was the gamble, you'd assume that the laptops would thermal throttle way below the physical Tjunction limit. As a matter of fact, they're still allowing themselves to reach very high temperatures even in common usage, despite an undersized (hence, to some extent, less reliable) cooling solution. That's kinda hard to explain as a sensible choice.
>the XPS 13 Plus’ fan was really struggling here because, boy oh boy, did this thing get hot.
After a few hours of regular use (which, in my case, is a dozen or so Chrome tabs with Slack running over top), this laptop was boiling. I was getting uncomfortable keeping my hands on the palm rests and typing on the keyboard. Putting it on my lap was off the table.
> not bulky gaming laptops with lots of cooling & ventilation
Those also have cooling problems. I bought a bulky one with 3 fans just because it had a nice processor. It couldn't sustain high performance under load for more than 5 seconds even with the fans maxed out. Compiling some code pushes CPU temperatures into the 80-90 °C range. Scrolling a chat in WhatsApp web also overheats my laptop.
> It's only a problem if throttling takes them below the advertised base clock under normal conditions.
Seems like a bit of a contradiction?
Dell said that my laptop would have an i7-7700HQ at 2.8 GHz + turbo to 3.something, and a GTX 1050m.
The laptop Dell sent me behaved like this under load: it goes to the max turbo speed, overheats within a few seconds to a minute, and then throttles to 800 MHz.
It's like if someone advertised a car as having a 280 HP engine, but the engine controller limited it to 100 HP because it had an inadequate cooling system and would overheat at any more load. It is deceptive.
With the laptop, underclocking can fix the CPU throttling - mine can now sustain the max turbo speed forever at 70 degrees. But that's like buying the 100 HP car and modding it to get to 280 - you were sold a faulty product. In the case of the laptop it's fixable in software so that's not as big of a deal, but how many normal people do you think would be willing to mess with their CPU voltages? Or even be aware of the throttling?
Even after underclocking the CPU, I cannot use it at the same time as the discrete graphics card. If I do, the combined heat makes the CPU once again go to 800 MHZ.
Expecting to be able to use the hardware my computer was advertised as having is not having unrealistic expectations.
> I'm a little confused at what's "sturdier" about a gaming laptop as well.
In my experience most gaming laptops are made of metal or thick plastic and seem more durable. I actually had a MSI laptop, it was a tank - like the revered Thinkpads, but better. Dropped it from a few feet and it only got a scratch on the surface.
> A gaming laptop is not really a laptop at all by comparison. They still get less than 4 hours of battery life under load, they're an inch or more thick, they're heavy. Many of them do not fit in backpacks. Gaming laptops are essentially designed for plugged in operation.
That's why I got the XPS 15. Had I known that its performance was a fraction of what was advertised I would have ignored this whole category of deceptive laptops and bought a gaming laptop, even though they have all these downsides.
> Especially when unplugged which will cause Alder Lake to significantly drop in performance.
At least in a laptop, it's not just when you unplug the laptop that performance drops. You've also got to have enough volume in the laptop to shoehorn in a major cooling system if you're going to keep the P series processors from throttling.
For instance, Lenovo's thin and light ThinkPad X1 Yoga has two fans but still throttles:
>Unfortunately, the laptop got uncomfortably hot in its Best performance mode during testing, even with light workloads.
>the XPS 13 Plus’ fan was really struggling here because, boy oh boy, did this thing get hot.
After a few hours of regular use (which, in my case, is a dozen or so Chrome tabs with Slack running over top), this laptop was boiling. I was getting uncomfortable keeping my hands on the palm rests and typing on the keyboard. Putting it on my lap was off the table.
> We have the exact same machines, yet mine somehow basically never has its fan on running Linux and compiling Rust, whereas theirs is often audible while running Windows with a couple of chrome tabs open and outlook.
I think some of this is just poor defaults. Every windows laptop I've had in the last 10 years has defaulted to a thermal management profile that ran the fans aggressively. Usually you have to install some crapware from the manufacturer (it's "Dell Optimizer" on my current machine) that allows you to change the thermal profile to quiet mode, and it's totally fine after that.
>Happens to some crappy laptops. These are basically irrelevant details.
Don't most modern (>2010) CPU's thermal throttle until they are back within operating temps? You'd have to stuff a laptop inside a backpack while maxing it to get it to overheat to the point of resetting
I'm not so sure I agree. My old laptop (still in use) is a Dell Precision m4800. It has a quad-core i7, and is so thick and heavy the word "laptop" is kind of a joke. It has massive heatsinks and fairly loud fans. Still it will throttle back after ~90 seconds of "make -j 4" or other heavily parallel jobs.
If you have a laptop that will run at 100% load indefinitely, it's only because the manufacturer has chosen a low power CPU.
> For something close to home, imagine a gaming laptop that runs on full performance mode without generating any heat. Imagine datacenters running full workloads without needing cooling.
Aren't there other components like transistors that will still generate heat?
Because of crappy CPU design and marketing. I have a work laptop (HP) with a 4 cores i5. When i do some work the fan is always at maximum speed and only one core is running because of thermal throtling. And the laptop is barely usable.
> Laptops shouldn't be using boost anyways, because their form factors and CPU coolers just can't handle the heat output.
That's quite a sweeping statement. The adequacy of cooling seems to depend a lot on the device and its configuration.
I've had two small form-factor ThinkPads at default configuration over the last nine years, and there have been zero problems with heat. The CPUs have conservative TDP limits, and the cooling seems adequate for that.
One of the laptops ended up with a broken keyboard after ~seven years, but if that hadn't happened, it would probably still be in daily (and not always particularly light) use, as it had been until then.
I'm sure some manufacturers and models choose their parts less conservatively, and put too powerful CPUs or GPUs (or set their cTDP too high) in a chassis that can't really handle it. For them, the maximum turbo allowed by their CPU/configuration might be too much over prolonged periods. Some of those devices might end up failing due to thermal issues within some years.
But for more conservatively configured laptops (such as business ones), disabling turbo would probably quite needlessly limit their performance. Unless you're aiming for a much, much longer lifespan than almost anybody uses their devices.
>they only have to dissipate about 20W of heat more at peak
That's a hell of a lot of extra heat in a thin laptop. Especially if a big chunk of the market values silence. An office full of laptops all sounding like airplanes isn't ideal.
Every laptop I've used is thermally limited if you try to do anything interesting computation wise. Simple things like 8 minute compiles turn into 12 minutes on a laptop, with fans at full blast.
The versatility of a laptop doesn’t mean that it should be expected to violate the laws of physics, or only use chips with maximum TDP such that it is always comfortable on your lap.
Having a chip which can max out thermal load while plugged in at your desk, with the expected thermal results, and then throttle down when you go mobile, again with the expected thermal results, is actually the best of both worlds.
And with one click the user can actually choose which power mode they want to operate in.
A laptop that throttles back to avoid getting hot when you need the CPU/GPU operating at peak performance would be much less useful, particularly for professional use.
Many, if not most, desktop-replacement laptops with 4+ cores are thermally limited on compute, and will throttle back under extended high load. I see it as a compromise of the form factor rather than dishonesty per se.
> I have a T420 and have major heating issues with it playing games.
In my experience, almost no consumer laptop is designed with a gaming thermal load in mind (aka heavy cpu + max gpu for extended periods of time). I'm not even sure it's possible in a conventional laptop case.
... I know this is completely useless advice, but don't do heavy gaming on a laptop without expecting problems. There are other form factors much better thermally suited.
tl;dr: mobility/thermal-tolerance/performance, pick two
>"The diagram says 'flowing air reaches the same temperature as the heat spreader'
So both will happily stay at CPU melting point.
They say that - "The Mini can dissipate up to 5 Watts of heat, while the larger Pro models can dissipate up to 10 Watts." which is definitely not enough to run performance laptops on sustained load.
>"but this is a shallow dismissal."
See the above. I think it is not dismissal that is shallow.
We're talking about the current state of the real market here, not abstract hypotheticals. Laptops overheating at 30% CPU usage is not a widespread issue in the real world; to a first approximation, the only way to get an ultrabook's CPU to thermally throttle is to keep at least one of its cores completely busy so that the processor stays in its boost state long enough to pump out serious thermal energy. Bursty workloads give the CPU too many opportunities to cool off.
Eh? Probably THE most common workload for a laptop (opening a webpage) is multi-threaded. And even consumers multi-task. As soon as you have multiple processes, you can use multiple cores even without multi-threading support.
> Plus it's exceedingly pointless to do lengthy multi-threaded development on a laptop, it's going to overheat and under-clock.
The promise of these laptops is that they won't. As you say, their power consumption is a lot lower than competing chips, and it's that power that produces the heat.
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