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tekno

macrumors 6502a
Original poster
Oct 15, 2011
840
4
My (limited) understanding is that it's the CPU.

But right now my MacBook Air is whirring loudly even though only Chrome, iWeb and Mail is open. The CPU is at 84 degrees (is that normal?) even though usage is 2% User, 1% System, 97% Idle.

Activity Monitor doesn't appear to show anything unusual.

So how can I find out why my Mac is so hot and battery life suddenly so bad?
 
I'm amazed! Honestly thought someone on here might be able to tell me why my Mac was getting so hot, but I guess that would require some genuine computer knowledge rather than geeky internet knowledge which is probably all that people who frequent forums have.
 
I'm amazed! Honestly thought someone on here might be able to tell me why my Mac was getting so hot, but I guess that would require some genuine computer knowledge rather than geeky internet knowledge which is probably all that people who frequent forums have.

I just now saw this thread and was about to answer your question, when I saw this post. If you want to throw a childish temper tantrum and insult forum members who you don't know, simply because they didn't respond to your thread as fast as you wanted, I'm no longer motivated to try to help. You're on your own. I'm sure someone will overlook your rudeness and reply, but I won't waste my time. :rolleyes:
 
It's the many transistors buried deep inside your CPU and GPU.

when working = using many if not all, then it uses more electricity.
When electricity runs through millions of transistors they get hot, because of the resistance in the wire, mind you they are 32 nano meter wide.

but of course the rest of the system gets hot too, partly from being used and mostly from dispersing heat from the CPU and GPU.

it's like a light bulb getting hot.

if you want to know more, then it's the electrons passing by the copper/gold/other rare metals atoms, bumping into them causing them to move about, which is energy = heat.
 
My (limited) understanding is that it's the CPU.

But right now my MacBook Air is whirring loudly even though only Chrome, iWeb and Mail is open. The CPU is at 84 degrees (is that normal?) even though usage is 2% User, 1% System, 97% Idle.

Activity Monitor doesn't appear to show anything unusual.

So how can I find out why my Mac is so hot and battery life suddenly so bad?

Chrome is often, in my experience, a processor & memory hog. I rarely use it myself but a good number of my trouble calls involve sluggish performance when Chrome is installed and running. I would switch to Safari or Firefox and consider disabling Flash if the heat bothers you. Also make sure the Mac is on a flat hard surface (not a lap, covers, cushion, etc) and that the keyboard & rear vent aren't obstructed.

Even then though, what you're describing sounds like pretty normal behavior for the vast majority of Macs. As someone else said, "they run hot" which is absolutely true. It's been that way since the early G4's and I'm sure they'll stay that way for years to come.

I'm amazed! Honestly thought someone on here might be able to tell me why my Mac was getting so hot, but I guess that would require some genuine computer knowledge rather than geeky internet knowledge which is probably all that people who frequent forums have.

And way to go asking for help then being a tool. So because someone didn't answer you between the evening and 3am you get all pissy and throw a tantrum. Not the best way to win folks over. Calm down, don't check the thread every 20 minutes, come back tomorrow, etc... Not getting a reply in the first 12 hours isn't a valid reason for throwing a fit.
 
I'm sure someone will overlook your rudeness and reply,

Well would you look at that - someone did! They were informative, helpful and someone even made a light-hearted comment about dragons. And all without getting personally offended and wasting their time telling everyone. (Thankfully I have tonnes of free time at my disposal)

You should take a leaf out of their book.
 
The CPU isn't the only source of heat, though it's the most common. If you're looking for actual troubleshooting, you've mostly ruled out the CPU (Flash is often a hog, but that would show up in Activity Monitor), so the only other possible culprits are GPU or poor airflow due to dust buildup or blocked vents. This is assuming the computer isn't just running at a normal temperature--you didn't say if that was 84C or 84F (84C is rather hot but within spec for the CPU, 84F is very cool). The hard drive and ancillary chips also generate some heat, but in a MacBook Air neither will generate significant amounts.

I'd offer more detailed help than that narrowing it down to one of those, but a little life lesson, using your free time to disparage the people you're asking for help generally results in less helpful and detailed responses. The correct response to someone pointing that out to you is to apologize for getting worked up unnecessarily, not get irate.

Kudos to dan1eln1el5en and Mr Rabbit for taking that much extra time to answer after you insulted them, though.


Wiggly amps.
I love that this answer is, technically, entirely correct.
 
Being friendless and unemployable will do that.

That is true. People with no friends and no job would indeed have plenty of spare time.

In my case I had taken the day off to wait in for the delivery of some furniture. And I've taken today off to spend it with my partner who also has the day off. That's the great thing about owning a company - I can take off as much time as I like.
 
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