MacBook Air and external monitors

[pupup]

I have my 2011 MBA plugged to an external monitor (Aluminum Cinema Display 20-inch 1680x1050, nothing fancy) and the fan turns on and gets noisy after 5/10 minutes.

Does this happen with newer MBA like the 2014 and 2015?

 

[motrek]

I have my 2011 MBA plugged to an external monitor (1680x1050, nothing fancy) and the fan is turns on and gets noisy after 5/10 minutes.

Does this happen with more modern MBA like the 2014 and 2015?

It shouldn't do that with any model, just because you plug it in to a monitor.

What does Activity Monitor say?

 

[Boyd01]

I used my 2011 MBA with an ancient 23" Apple Cinema display (1920x1200) extensively and never noticed this issue. I agree that something else is going on.

 

[pupup]

It depends but it's usually Safari, not necessarily with YouTube, and kernel_task.

 

[MyopicPaideia]

Nope, nothing like that. Got my 2013 11" MBA base model hooked up to a 21" 1080p Dell monitor and 12TB RAID 10 external enclosure, and haven't had any fan issues at all.

 

[26139]

This one weird trick worked for me...

...though it may not work for you.

Open Activity Monitor, quit Bash.

Always, always, always reduced processor load and fan noise after turned off on my 2012 MBA.

 

[chrispyfur]

Bash is the Unix shell, before you quit that (is it usually running when you're not using terminal?) find out what processes are running in it...

 

[26139]

Hmmm....

Bash is the Unix shell, before you quit that (is it usually running when you're not using terminal?) find out what processes are running in it...

It's never been running on any Mac I've had, without launching terminal, except for my MBA.

I know that sounds weird, but two wipes didn't change it.

 

[Dweez]

There's no logical or programmatic reason that simply plugging in an external monitor would load up the system, causing the fans to spin up. FWIW I've been running an external 23" since I picked up my mid 2013 MBA.

 

[Boyd01]

Thing is, if I plug my MBA into my 46" Sony TV with an HDMI adapter and watch a movie, the battery level drops much faster than watching it on the built-in screen. Even if I dim the built-in screen all the way down, the battery still runs down faster when using the external screen.

So more energy is being used to drive the second screen, and that might result in a warmer computer. However, I have never seen the fan kick in while doing this.

 

[motrek]

Thing is, if I plug my MBA into my 46" Sony TV with an HDMI adapter and watch a movie, the battery level drops much faster than watching it on the built-in screen. Even if I dim the built-in screen all the way down, the battery still runs down faster when using the external screen.

So more energy is being used to drive the second screen, and that might result in a warmer computer. However, I have never seen the fan kick in while doing this.

Possibly it takes more GPU (CPU?) power to scale the video frames up to the TV's higher resolution. During normal (non-video) use this shouldn't be much of an issue.