Fans on New MacBook Air ?

[slomojoe]

can someone explain this to me

I just bought a MacBook Air 2019 which I like a lot so far and mostly it runs very quiet and fans off or so low I can't hear them

but I recently ripped a backup of my audible audiobooks (with "open audible") to mp3 format (and was transferring some files from one external disc to another as well) and the fans just started roaring super loud

what is the technical reason this happens, i have 8gb of ram if that makes a difference) and open audible is a 64 bit application if that makes a difference ?

I just am curious why it goes from dead silent to jet plane engine primarily only when using this application

 

[auxbuss]

Because converting files from one type to another is a sustained CPU-intensive task. Hence, the CPU gets hot and stays hot, and so the fan kicks in to keep it within limits.

 

[slomojoe]

interesting, so most tasks then are switiching from one process to another, that makes sense

but what about browsers where we have a lot of tabs open ?

as you say, probably any sustained audio, video and the like will kick the fans up

what is really interesting to me is that i used the exact same program ripping the exact same files on my previous macbook 12 which had the m3 1.1 processor, the absolute lowest entry level 2015 model and it had no fan at all and ripped at the exact same speed without any fans ... go figure ... anyway, thanks for the reply

 

[AustinIllini]

Sounds like you have a perfectly fine functioning machine.

 

[slomojoe]

yeah, i know the machine must stay cool and there must be something programmed somewhere because i ripped a long book, 1 single book and the fans came on right away and stayed on even though the machine was sitting idle before and was cool

as i say, my fanless macbook 12 ripped just as fast without any fan or more noticeable heat which is interesting

 

[Falhófnir]

The chip in the MBA is actually designed as a passively cooled part, but that means it needs to throttle itself to regulate temperatures. The fan is added in so it can run at higher clocks indefinitely, which improves performance, but does mean you get some fan noise when you make the chip do work above the level that the chassis can passively dissipate heat. Sometimes what seem like oddly pedestrian activities can load the chip more than expected, which will kick in the fan, this is especially common for poorly optimised programs, but can be triggered by a lot of things.

 

[slomojoe]

The chip in the MBA is actually designed as a passively cooled part, but that means it needs to throttle itself to regulate temperatures. The fan is added in so it can run at higher clocks indefinitely, which improves performance, but does mean you get some fan noise when you make the chip do work above the level that the chassis can passively dissipate heat. Sometimes what seem like oddly pedestrian activities can load the chip more than expected, which will kick in the fan, this is especially common for poorly optimised programs, but can be triggered by a lot of things.

interesting thanks, it is usually silent for the simple basic stuff but kicks in when i rip aax files ... my macbook 12" using the same program ripped the same files at the same speed and of course had no fans and didn't seem to get hot, in fact it seemed to feel cooler to the touch than my new mb air ... hmmm?

another question ... would the macbook pro fans likely come on doing the same rip with the same program ? it has a higher power chip and i wonder if that means it would exert less work and therefore need less cooling ?