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motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305
Lots of talk about fanless MBAs. I don't see how it's possible.

I have a new 2014 11.6" MBA which has the lowest power CPU/GPU of the range.

Normally it runs very cool and it might be able to run without the fan. But if I run a compute-heavy task, the CPU gets up to 80C in about 10-15 seconds and it hits 90C and the fan spins up to a pretty good clip after ~60 seconds.

Now, Broadwell is supposed to decrease power consumption by 30% over Haswell. That's great, but surely the current MBA's fan improves cooling by at least 30%. (Remember, it always runs at 1200 RPM or more.)

So I would expect a fanless MBA with Broadwell to hit the same CPU temperatures as the current MBA. Might be fine for light use, but under heavy use there's no fan to spin up, so it would have to resort to major CPU throttling. Which basically means crap performance if you're doing anything serious. I can't see Apple going down that route for one of its nice, expensive laptops.
 

Ramius

macrumors 6502
Nov 2, 2008
492
197
Johnny Ive is the answer. He is the chosen one that will make it happen.

He will create an "ingenious cooling solution" that uses liquid metal to evenly distribute heat away from the processor into the chassis of the machine. "Allowing us to create a completely silent Macbook, so you will not get disturbed while enjoying your content" - Typical thing he would say in the ad.
 

mad3inch1na

macrumors 6502a
Oct 21, 2013
662
6
Lots of talk about fanless MBAs. I don't see how it's possible.

I have a new 2014 11.6" MBA which has the lowest power CPU/GPU of the range.

Normally it runs very cool and it might be able to run without the fan. But if I run a compute-heavy task, the CPU gets up to 80C in about 10-15 seconds and it hits 90C and the fan spins up to a pretty good clip after ~60 seconds.

Now, Broadwell is supposed to decrease power consumption by 30% over Haswell. That's great, but surely the current MBA's fan improves cooling by at least 30%. (Remember, it always runs at 1200 RPM or more.)

So I would expect a fanless MBA with Broadwell to hit the same CPU temperatures as the current MBA. Might be fine for light use, but under heavy use there's no fan to spin up, so it would have to resort to major CPU throttling. Which basically means crap performance if you're doing anything serious. I can't see Apple going down that route for one of its nice, expensive laptops.

Or there could be a major redesign of the heat sink. Remember that the iPad is fanless.

I am not saying you are wrong, but I bet that Apple has done quite a bit of prototyping with a fanless design. If there is a company that will release a fanless laptop, Apple will be the first one to do it correctly.

Matt
 

motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305
Or there could be a major redesign of the heat sink. Remember that the iPad is fanless.

I am not saying you are wrong, but I bet that Apple has done quite a bit of prototyping with a fanless design. If there is a company that will release a fanless laptop, Apple will be the first one to do it correctly. ...

The iPad is fanless but it also has basically the same guts as an iPhone, i.e., crazy low power compared to a Haswell or even Broadwell. There's no comparison.

Apple can't bend the laws of physics. They have always put a priority on making their systems as quiet as possible but there's only so much they can do. Remember the overheating G4 Cubes?
 

DePaulBlueDemon

macrumors 6502
Sep 27, 2010
250
40
I admit that a fanless design is intriguing, my 2011 Macbook Air's fans scream when streaming HD video for more than an hour. However, like you I just can't fathom how it can be accomplished with a decent CPU/GPU.
 

Pakaku

macrumors 68040
Aug 29, 2009
3,137
4,447
The iPad is fanless but it also has basically the same guts as an iPhone, i.e., crazy low power compared to a Haswell or even Broadwell. There's no comparison.

Apple can't bend the laws of physics. They have always put a priority on making their systems as quiet as possible but there's only so much they can do. Remember the overheating G4 Cubes?

So all Apple really has to do is build an iPad with a hinge and an AX chip that can run OSX.

It would be very crippled, but it would make the fanless idea possible.
 

RightMACatU

macrumors 65816
Jul 12, 2012
1,423
1,132
192.168.1.1
In deed, this will be very interesting to see how things develop. My 2013 Ultimate's fan just screams within a minute of loading Starcraft 2.
 

cyber16

macrumors 6502
Jan 12, 2013
487
28
The new Intel CPUs will only be drawing around 5watts under max load.
They can go passive cooling
 

mad3inch1na

macrumors 6502a
Oct 21, 2013
662
6
The iPad is fanless but it also has basically the same guts as an iPhone, i.e., crazy low power compared to a Haswell or even Broadwell. There's no comparison.

Apple can't bend the laws of physics. They have always put a priority on making their systems as quiet as possible but there's only so much they can do. Remember the overheating G4 Cubes?

Intel is releasing Broadwell processors for fanless laptops this year. It isn't that farfetched that Apple could do it this year, let alone in a year or two.

https://www.macrumors.com/2014/08/11/intel-core-m-broadwell-processors/
 

motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305
Intel is releasing Broadwell processors for fanless laptops this year. It isn't that farfetched that Apple could do it this year, let alone in a year or two.

https://www.macrumors.com/2014/08/11/intel-core-m-broadwell-processors/

Sure, but they deliberately make it almost impossible to figure out how said processors will perform vs. existing processors.

There are some figures thrown out like "19% faster on office workloads" but that hardly means anything.

What about a sustained, CPU-intensive workload? If Broadwell "only" decreases power consumption by 30% and Apple wants to maintain similar performance with current laptops then they will need to use a fan.
 

ha1o2surfer

macrumors 6502
Sep 24, 2013
425
46
I am a little scared of laptops that claim they want to go fanless.. I can see lots of throttling in their future. I mean, my quad core tablet is one thing with a SDP of 2watts.. but at best I get 1/4 the power of a baseline 11 macbook air. I'm curious how Intel goes about testing this claim.
 

Nozuka

macrumors 68040
Jul 3, 2012
3,527
5,996
HP, Lenovo and Dell have announced and shown their fanless Tablet/Notebook 2-in-1 devices already, with the new Core M chips.

Intel designed it to be fanless, so there's no reason someone like Apple wouldn't be able to do it too.
 

motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305
HP, Lenovo and Dell have announced and shown their fanless Tablet/Notebook 2-in-1 devices already, with the new Core M chips.

Intel designed it to be fanless, so there's no reason someone like Apple wouldn't be able to do it too.

Sure, it's a question of Apple's performance targets.

They could have released a fanless MacBook based on the Intel Atom several years ago... and its performance would have been terrible.

Apple has traditionally used Intel's faster, higher-end parts and I don't see why they would reverse that trend now. The Core M is Intel's slowest Broadwell.

Of course a passively cooled computer would be nice but these days there's not much of a disadvantage to having a fan. The fan on my 2014 MBA is barely audible--I have to move my ear to within ~2 inches of it to hear it at all. And I have pretty good hearing. And the processor is efficient enough that the fan almost never spins faster than 1200 RPM. Only when I'm doing something that's unusually compute-heavy. And at that point, I'd rather hear a small amount of noise from a fan vs. experience CPU throttling.
 

Nozuka

macrumors 68040
Jul 3, 2012
3,527
5,996
They could have released a fanless MacBook based on the Intel Atom several years ago... and its performance would have been terrible.

Apple has traditionally used Intel's faster, higher-end parts and I don't see why they would reverse that trend now. The Core M is Intel's slowest Broadwell.


apple also likes to make their hardware as slim and light as possible.

and the macbook air is not aimed at performance oriented people, its really more about portability. the pro line is for performance.

it would make sense to go this route with the air, especially to further differentiate the pro and air lines.

the core M chips are alot faster than the atom chips too.

http://www.pcper.com/reviews/Processors/IDF-2014-Intel-Shows-Core-M-5Y70-Performance-Numbers


edit: ah there it is.. the macbook air competition is already going with the fanless design. the air is an ultrabook afterall.
http://www.asus.com/Notebooks_Ultrabooks/ASUS_ZenBook_UX305/
 
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motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305

Interesting article, thanks. Notice the part about how the Core M uses 15W at maximum clock speed--interesting and surprising since that's the same as the Haswells that are in the current MBAs.

So if Apple wants to make a Broadwell laptop with the same sustained performance as their current laptops, they need to have a cooling system that's exactly as effective as the one they have now, i.e., they need a fan.

Otherwise, there's going to be a big performance hit in some situations. I can't see them taking this big of a step backwards. It's one thing to differentiate your products more, i.e., make the MacBook Pro significantly faster than the Air... it's another thing to say that your new, redesigned 2015 laptop is half as fast as your 2014 laptops when you're playing video games etc.
 

Nozuka

macrumors 68040
Jul 3, 2012
3,527
5,996
it's not really a step backwards. it's prioritizing one thing (portability and efficiency) over another.
most people just use their air for some surfing, e-mail, youtube, payments... most computers have long been overpowered for that.

if you really need high performance you'll be drawn to the pro.

but we will have to wait and see. i'm not saying its going to happen - i'm just saying its very much possible.
 

NewbieCanada

macrumors 68030
Oct 9, 2007
2,574
37
One thing that concerns me is the temperature from a user point of view.

I used to have a 2013 MBA. Not only did it run virtually silent most of the time, it ran COOL. I could almost always use it directly on my lap, even when wearing shorts. iPad Air is fanless, but definitely gets warm. I'm not sure I'd want to make the trade-off between fan and coolness.
 

motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305

This is kind of a worthless statistic though... Intel can hit basically whatever number they want for average power (or even "maximum" power over a small period of time) by manipulating the clock speed.

The real question is, how much power does the chip take for maximum, sustained performance and the answer seems to be 15W according to the previous article that was posted.

I just can't see Apple taking the performance hit of going fanless. I imagine their position is that if you don't need a powerful computer, or if you need a "computer" that's 12mm thick instead of 17mm, you could be using an iPad (with or without a keyboard dock/cover).
 

motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305

This is probably related to SDP/TDP controversy:

http://www.theverge.com/2013/1/9/3856050/intel-candid-explains-misleading-7w-ivy-bridge-marketing

But also, all of those numbers on Intel's page might be right, I'm sure the chip CAN turbo boost up to 2.6GHz, but that would be for short amounts of time to make sure they stay within their power/thermal envelope.

That's pretty different from a chip that can run at 2.7GHz indefinitely like in my 2014 MBA.
 

Ramius

macrumors 6502
Nov 2, 2008
492
197
I really wish they would redesign a new charger. The one now was nice in 2008, but now it feels big. It takes so much space in my fancy messenger bag that sometimes I go to work without it, and hope I wont need it.
 

motrek

macrumors 68030
Original poster
Sep 14, 2012
2,613
305

MarvinHC

macrumors 6502a
Jan 9, 2014
834
293
Belgium
I don't believe in a fanless design. When I see how hot my iPhone 5S sometimes gets, one would almost think they could do with a fan in them...
 

MacModMachine

macrumors 68020
Apr 3, 2009
2,476
392
Canada

chances are if apple use this it will be some custom variant of it.

i believe they will be trying to push retina res. on the new airs whether it be internal or external support.

this cpu i think would be plenty for me, maybe not others though.

Another cool option would be combining this cpu with a A8 variant ARM cpu to allow apps that support arm to be run on that low wattage SoC.
 
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