New MacBook Air has useless fan?

[amyk]

Your thoughts?

[wraper]

It might create some airflow over that heatsink if enclosure creates sort of air guide from the heatsink to the fan. However even if it's made so, it's a very crappy cooling nonetheless. No way it can even remotely perform as a heatpipe and proper heatsink behind the blower fan.

[Someone]

Not a new discovery or a new design:
https://www.ifixit.com/Teardown/MacBook+Air+13-Inch+Retina+2018+Teardown/115201
Cooling a 7W ultra low power CPU with integrated graphics is a little different to the hardware required for most laptops.

[BravoV]

Suddenly the words "planned obsolescence" pop out in my mind. 

[PartialDischarge]

Whenever Louis I'm the man Rossman goes from repairman to design engineer he is just embarrassing himself, covered by the suppport of a herd of fans that will cheer whatever he says against apple.

I think the ideas was to use the cavity from the convex shape of the clamshell chassis as an air current rectifier, and suck air from one side, through the fins, to the other side where the fan's inlet plane is located, then blow the air through the outlet port.

That is how it works

I'm pretty sure Apple did the simulation, and it works

I'm pretty sure they placed temp probes inside

However even if it's made so, it's a very crappy cooling nonetheless. No way it can even remotely perform as a heatpipe and proper heatsink behind the blower fan.

It is not a crappy design based on your (or my) impression. It will perform or not based on real data, steady state and transient temperature profiles.
Judging a cooling system by its looks its worse than judging a circuit by its looks, you need measurements.

[BrianHG]

It is not a crappy design based on your (or my) impression. It will perform or not based on real data, steady state and transient temperature profiles.
Judging a cooling system by its looks its worse than judging a circuit by its looks, you need measurements.

But still, wouldn't a properly piped fan design mean the fan would not have to work as hard?
More efficient meaning a slower fan, saving battery power and lower RPM means lower noise...

[Cyberdragon]

But still, wouldn't a properly piped fan design mean the fan would not have to work as hard?
More efficient meaning a slower fan, saving battery power and lower RPM means lower noise...

The CPU on the MacBook and MacBook Air is supposed to only operate when you open a program. Otherwise, it is supposed to stay idle.
That's why we have hardware video decoder, hardware encryption coprocessor and hardware {put_function_in_there}.

It is not a number crunching machine. If you need a transcoding warrior or a simulation powerhouse, you are buying the wrong computer.

That is still poor design then if the cooling is the limiting factor of PC performance. That's like shipping a car with a tiny radiator and saying "don't expect to rally with it".

[Someone]

It is not a crappy design based on your (or my) impression. It will perform or not based on real data, steady state and transient temperature profiles.
Judging a cooling system by its looks its worse than judging a circuit by its looks, you need measurements.

But still, wouldn't a properly piped fan design mean the fan would not have to work as hard?
More efficient meaning a slower fan, saving battery power and lower RPM means lower noise...

It might cool the CPU at the other end of the heat pipe better, but what about all the other parts on the PCB? Having the airflow across almost the entire motherboard cools those parts better than the plastic enclosed laptops that carry all the heat around in pipes.

That is still poor design then if the cooling is the limiting factor of PC performance.

If you can find a single thin and light high performance computer (gaming laptop with dGPU and i7/i9-HQ/HK under 20mm thickness) without thermal throttling during CPU+GPU dual stress testing, I'd like to hear about it.

Even oversized gaming "laptops" from Alienware etc hit thermal limits on many of their configurations.

[legacy]

That's like shipping a car with a tiny radiator and saying "don't expect to rally with it".

Indeed! Facts are: my brother's Mac Pro got seriously damaged for overheating during an FEM analysis and repaired TWO times before it got replaced with a serious laptop.

[maginnovision]

My HP gaming laptop doesn't throttle... It's also 35mm thick and quite hefty. When I installed the second drive the cooling appeared to be adequate but it is a little more of a dust trap than I'd like.

[langwadt]

But still, wouldn't a properly piped fan design mean the fan would not have to work as hard?
More efficient meaning a slower fan, saving battery power and lower RPM means lower noise...

The CPU on the MacBook and MacBook Air is supposed to only operate when you open a program. Otherwise, it is supposed to stay idle.
That's why we have hardware video decoder, hardware encryption coprocessor and hardware {put_function_in_there}.

It is not a number crunching machine. If you need a transcoding warrior or a simulation powerhouse, you are buying the wrong computer.

That is still poor design then if the cooling is the limiting factor of PC performance. That's like shipping a car with a tiny radiator and saying "don't expect to rally with it".

most cars will overheat if you take them on a racetrack and drive in anger, cooling system is insufficient for the high power of constant acceleration and braking keeping the average speed down

[Kilrah]

If you can find a single thin and light high performance computer (gaming laptop with dGPU and i7/i9-HQ/HK under 20mm thickness) without thermal throttling during CPU+GPU dual stress testing, I'd like to hear about it.

That's irrelevant. If something thermal throttles because the cooling solution when it would have been easy to do better without drawbacks then it's stupid design.
My Retina macbook throttles, but in this case the design intent was for it to be fanless so it's normal. But IF that macbook air throttles because of the colling design when a heatpipe could have prevented it then it's poor design since you're not losing something by putting one.

Lots of ifs since we don't know if it does, but then again we can expect it to since pretty much every Mac does.

[wraper]

I'm pretty sure Apple did the simulation, and it works

I'm pretty sure they placed temp probes inside

I'm pretty sure Apple made warranty extension programs (of which buyers usually are not aware of or on terms most of them will miss it) multiple times because of chip dying as a consequence of overheating.

[wraper]

It might cool the CPU at the other end of the heat pipe better, but what about all the other parts on the PCB? Having the airflow across almost the entire motherboard cools those parts better than the plastic enclosed laptops that carry all the heat around in pipes.

Adding heatpipe with a heatsink behind the blower fan does nothing to prevent fan from moving air across the PCB from intake side .

[SiliconWizard]

If you can find a single thin and light high performance computer (gaming laptop with dGPU and i7/i9-HQ/HK under 20mm thickness) without thermal throttling during CPU+GPU dual stress testing, I'd like to hear about it.

That's irrelevant. If something thermal throttles because the cooling solution when it would have been easy to do better without drawbacks then it's stupid design.

You're welcome to design better within Apple's constraints (size, weight, noise) and submit that to them - I'm sure they'd be happy to hire you.

Performance laptops that can run for extended periods of time at full clock speed are usually very chunky and heavy. They often look more like "portable computers" than thin laptops.

[Kilrah]

You're welcome to design better within Apple's constraints (size, weight, noise) and submit that to them

Adding a heatpipe in the free space we see would not make more noise, make the machine any bigger or weigh significantly more.

- I'm sure they'd be happy to hire you.

The constraints they set for themselves and the compromises that result of it are not ones I would agree to work towards.

[Someone]

It might cool the CPU at the other end of the heat pipe better, but what about all the other parts on the PCB? Having the airflow across almost the entire motherboard cools those parts better than the plastic enclosed laptops that carry all the heat around in pipes.

Adding heatpipe with a heatsink behind the blower fan does nothing to prevent fan from moving air across the PCB from intake side .

There isn't space for a heat pipe and associated heatsink in that layout. As mentioned above you'd be radically redesigning the entire system to fit that sort of design in, and there is unlikely the space to fit heat pipes without impacting or compromising something else. If you're convinced its so easy, make a cooling package for some of these laptops and sell it to all these people who want better cooling, [sarcasm]it'll be a huge market and you'll be rich[\sarcasm].

[Someone]

You're welcome to design better within Apple's constraints (size, weight, noise) and submit that to them

Adding a heatpipe in the free space we see would not make more noise, make the machine any bigger or weigh significantly more.

So you have the dimensions of the free space available and can suggest a suitably thin heat pipe? There aren't any that will fit in that actual space, there are plenty of high resolution photos for you to work from:
https://www.ifixit.com/Teardown/MacBook+Air+13-Inch+Retina+2018+Teardown/115201
compare the space required to fit such heat pipes in other similar laptops:
https://www.ifixit.com/Teardown/MacBook+Air+13-Inch+Early+2015+Teardown/38266
https://www.ifixit.com/Teardown/MacBook+Air+13-Inch+Mid+2013+Teardown/15042
https://www.ifixit.com/Teardown/MacBook+Air+13-Inch+Mid+2011+Teardown/6130

- I'm sure they'd be happy to hire you.

The constraints they set for themselves and the compromises that result of it are not ones I would agree to work towards.

All products have compromises, they traded off things you don't value as much against something you think is more important. Good for you! Feel free to buy a different product which meets your needs instead of insisting all laptops should be bulky bricks that never thermally throttle. But it seems the market is very happy with thin and light products with reduced compute performance.

[NiHaoMike]

You're welcome to design better within Apple's constraints (size, weight, noise) and submit that to them - I'm sure they'd be happy to hire you.

Easy way to get better cooling is to add thermal pads to use the aluminum case as part of the heatsink. The problem is that the thermal pads, while cheap, do cost something and they try to cut every last fraction of a cent they can get away with.

[wraper]

There isn't space for a heat pipe and associated heatsink in that layout.

Really. If there is enough space for that heatsink, sure there is enough space over PCB for a flat heatpipe. Heatsink adds like 1 centimeter behind the fan, with the same thickness as fan itself.

If you're convinced its so easy, make a cooling package for some of these laptops and sell it to all these people who want better cooling, [sarcasm]it'll be a huge market and you'll be rich[\sarcasm]

One of stupidest arguments. It's not easy to add something to completed design. You cannot simply shrink the fan or cut a hole behind it. Not to say it's a custom fan. But at design stage it wasn't hard to do at all.

[wraper]

You're welcome to design better within Apple's constraints (size, weight, noise) and submit that to them - I'm sure they'd be happy to hire you.

Easy way to get better cooling is to add thermal pads to use the aluminum case as part of the heatsink. The problem is that the thermal pads, while cheap, do cost something and they try to cut every last fraction of a cent they can get away with.

Easy, but then instead of burning itself, CPU will burn your lap because enclosure will become hot.

[langwadt]

It might cool the CPU at the other end of the heat pipe better, but what about all the other parts on the PCB? Having the airflow across almost the entire motherboard cools those parts better than the plastic enclosed laptops that carry all the heat around in pipes.

Adding heatpipe with a heatsink behind the blower fan does nothing to prevent fan from moving air across the PCB from intake side .

why use a heat pipe to move heat to a heatsink in the fan output when you can use a heatsink directly mounted and in the
fan intake air? 

[BrianHG]

It might cool the CPU at the other end of the heat pipe better, but what about all the other parts on the PCB? Having the airflow across almost the entire motherboard cools those parts better than the plastic enclosed laptops that carry all the heat around in pipes.

Adding heatpipe with a heatsink behind the blower fan does nothing to prevent fan from moving air across the PCB from intake side .

why use a heat pipe to move heat to a heatsink in the fan output when you can use a heatsink directly mounted and in the
fan intake air?

The idea here is that the current fan design doesn't even try to move air anywhere in the design, that just a smidge of effort could have improved the situation without added cost, maybe even saving apple money in the long run.

[Someone]

There isn't space for a heat pipe and associated heatsink in that layout.

Really. If there is enough space for that heatsink, sure there is enough space over PCB for a flat heatpipe. Heatsink adds like 1 centimeter behind the fan, with the same thickness as fan itself.

If you're convinced its so easy, make a cooling package for some of these laptops and sell it to all these people who want better cooling, [sarcasm]it'll be a huge market and you'll be rich[\sarcasm]

One of stupidest arguments. It's not easy to add something to completed design. You cannot simply shrink the fan or cut a hole behind it. Not to say it's a custom fan. But at design stage it wasn't hard to do at all.

Your "argument" that with a completely different set of design goals the product could have been designed differently is the silly one. There is no way to fit a heatpipe cooling system in there without adding size and weight. Check the examples linked above of their previous products and see just how much volumetric space is needed, now find that wasted volumetric space in the design. The CPU is one thing that is cooled by the heatsink, but not the only thing.

[Someone]

It might cool the CPU at the other end of the heat pipe better, but what about all the other parts on the PCB? Having the airflow across almost the entire motherboard cools those parts better than the plastic enclosed laptops that carry all the heat around in pipes.

Adding heatpipe with a heatsink behind the blower fan does nothing to prevent fan from moving air across the PCB from intake side .

why use a heat pipe to move heat to a heatsink in the fan output when you can use a heatsink directly mounted and in the
fan intake air?

The idea here is that the current fan design doesn't even try to move air anywhere in the design, that just a smidge of effort could have improved the situation without added cost, maybe even saving apple money in the long run.

It looks live a very clearly designed air tunnel to myself and others, air comes in one end, passes across the main board with its heatsink, and is pushed out of the case by the fan. This has been done in all sorts of computers, laptop and desktop, over the years.