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Comment by paranoidrobot | Hacker News Reader

FTA:

> We also wonder about how Personal Safety will be able to do this type of always-on recording without generating excess heat, especially if your phone needs to be mounted in a position that’s likely to see a lot of direct sunlight.

That's what I immediately thought of. I can't see this working too well unless they solve the overheating issues.

I had my Google Pixel 7 Pro shut down due to overheating, on a reasonably hot day (~35C) where I was walking around and taking a bunch of photos.

I had to use my hands to absorb the heat, to cool it down enough to turn back on so I could call a Taxi and get somewhere cool.

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Presumably the device will do the recording with the screen turned off, so it will generate little heat internally. So I think placing most of the device behind something to shield it from sunlight should be enough to avoid heat issues.

Though I agree with others here that a cheap specialized dashcam device is much better.

I’d want to use the screen for navigation and the camera for Dashcam at the same time

not sure if you're using iOS, but I already made one for iPhone.

https://apps.apple.com/us/app/dashmap/id1638360259

Good luck. As soon as you tilt the screen towards you so you can read it, your dashcam is now capturing video off at some weird angle.

android auto

I always have my phone screen off while driving since it's hooked up via Android Auto, but I've had my phone shut off many times on warmer days. I'm not sure how I could reasonably shield it from sunlight and use it as a dash cam at the same time.

Still won't be enough. Driving I-5 from LA to SF on a reasonably warm day (85+F) means the phone will shut down within the hour if it's on the dashboard. I've specifically gotten a phone mount that attaches to the AC vents for that purpose.

I appreciate the thought, but unless it works up to at least 140F, it won't be useful

The Exynos based Tensor, made by Samsung is very hot. Google should've collaborated with QC or MT and used TSMC to make their SOC.

Snapdragons overheat just fine too, it's not a unique issue. Also what is actually overheating most in this scenario is not the SoC but a display. Open your phone of any brand and model and walk around with it unlocked in the bright summer sunny day outside. The screen will work at max brightness and would become insanely hot from the internal heat in very short time span.

>The screen will work at max brightness and would become insanely hot from the internal heat in very short time span.

It's the sun heating up the black non-reflective back of screen. Probably wouldn't be as much of an issue with transreflective displays. The display showing full brightness definitely contributes to the problem, but it's not the main culprit.

In my case with a Galaxy S9, it's the screen that overheats easily. It's a double whammy when in the bright outdoors, because sunlight hits the phone, and it needs to be bright so that the screen can be seen.

Good thing video recording can be practically fully offloaded to specialized blocks and doesn't need the main cores to be driven at high clock.

My iPhone heats up uncomfortably if I leave it in the sun even if I don’t use it. The SoC is irrelevant here.

Why are chips made by samsung vs tsmc are any different?

Samsung's foundries have struggled for the past few years to achieve their targets, whereas TSMC has continued improving at their projected rates. TSMC's process is now significantly ahead of Samsung's, such that the same designs are better on TSMC. These improvements are along the lines of fewer defects, higher switching speeds, less leakage, etc.

The Snapdragon 8 Gen 1 was made on Samsung's fabs. The 8+ Gen 1 is the same design on TSMC.

To be clear, this is for Samsung's processor foundries. Their DRAM and flash memory still appear to be industry leaders.

It's not even a recent thing. Way back when Apple used both TSMC and Samsung foundries for their A9 SoC's, the Samsung ones were measured to perform worse than the TSMC ones. https://arstechnica.com/gadgets/2015/10/samsung-vs-tsmc-comp...

It's just the gap has become more noticeable in recent years. (Notably with things like the Snapdragon 888 handwarmer).

To put it in perspective, the latest Tensor G2 is outperformed by the 2019 A13 Bionic in geekbench.

Why are cars made by Toyota and Ford any different?

A lot of different technical decisions have been made by different people along the way.

Both are producing same chips, maybe slightly different serial number. Perhaps better comparison would be why Chinese Tesla’s are better than American ones.

Or why airlines are refusing to take deliveries of Boeing planes from a certain factory but not the others. If it's difficult to maintain consistent quality inside a single company, it's no surprise that differences like this can show up in "identical" CPUs fabricated by different companies.

No, Samsung's processes and TSMC's processes are not the same. They were not making the same chip; they each were making chips based on the same input design, that had been targeted to two different processes.

Are Chinese Tesla's better than American ones? Is it just higher quality control because of a newer manufacturing setup there?

Quality of manufacturing. Think about a mechanical assembly manufactured within specifications but where one is at the upper bound of tolerance and things rattle a bit while the other is a perfect fit.

In most quality systems those parts are equivalent (they meet spec). If you need or want better parts, you tighten the spec.

A sibling comment to yours points out that TSMC has better processes. That's probably a better way to state it, they can hit a tighter spec at the same price point.

> In most quality systems those parts are equivalent (they meet spec). If you need or want better parts, you tighten the spec.

Components being equivalent within spec doesn't mean they have the same performance. It only means they are all acceptable for their intended use. That's why the Apple A9 from TSCM were performing better than the Samsung ones in the same way batches of products made from the same blueprints can have widely different failure rates.

These are quality of manufacturing issues and yes it is due to TSCM having better processes than Samsung. That's not a better way to state it. One is the reason of the other.

Car phone mount with a heat sink on the back could help a good bit.

Mounting it right behind an A/C vent might be much better.

There are special phone cases/holders designed for that. I'm pretty sure Google will sell those too. Not to mention this might be a camera recording the driver-distraction and not the road. So it doesn't have to be in the sun. Or even for passengers in a driverless car

> this might be a camera recording the driver-distraction

I'm not sure why you would want to use your phone to record yourself while driving to see if you're distracted.

To use AI to alert you to when you're not paying attention.

That seems like it might be reasonable feature to be built in to vehicle, but I can't imagine many people who are that prone to distracted driving to take the time set up such a feature every time they drive.

A mount that moves AC air directly to phone should work.

you can have direct sunlight heating up the phone on a day that AC is not needed

this issue needs to be handled by the device and not with external resources

Buy a white phone and don't put a case on it.

Or buy a white case. That’s what I did and it seemed to work, as a Sat Nav device at least. Not sure about recording video which will produce more heat.

ha! not in Australia you cant.

That sun is murder on hot phones.

Assuming it’s not a snowy winter day in Michigan… ;)

My pixel 4 died because of poor heat management.

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