Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Scott6666

macrumors 68000
Original poster
Feb 2, 2008
1,511
980
I have an MBA 1.6/80 which is silent when the fan is 2500. Unfortunately when I do anything that has CPU load above 15% for 30 seconds - 1 minute the fans spin up to 6200 and then stays there for a long time (5 minutes say) before it tries to slow down again (even if the CPU temp is 50-55 again. If I sleep and open again immediately it will usually slow down immediately to 2500. Doesn't matter what I run (videos, Parallels, whatever) if its above 15% or so the fan speeds up.

What I see on the boards are obviously the people who have this problem. What I would like is for all of you that DON'T have this please report in. I'd like to know that there are hundreds of you with OK fan behavior. Then I would know that mine is defective and I would get another. BUT if there is no one out there who doesn't have this issue than why bother to try to return; it's a design issue. I have definitely seen a couple posts where people do exchanges and end up just where they are in the beginning.

Let's hear from all of you WITHOUT fan issues.
 

mark34

macrumors 6502a
May 18, 2006
646
182
I think i have noticed the fan on heavy for a while a couple of times, but in general i am at 2,500 rpm. Not a problem I have noted, but I have admitedly not done much besides web browsing, slingbox, Office apps, iTunes, iphoto.
 

mac jones

macrumors 68040
Apr 6, 2006
3,257
2
when you say " virtually forever" how long is that?

Mine will stay at 6200 for about 5 min after it heats up for a while (runs demanding app for 5 10 minutes).

I consider this quite normal and would not expect any change. However, I would imagine that this is a 'software' issue as I imagine it does not need to be at 6200 for that long because the istats say cpu has cooled down pretty much right away after the offending app is closed.

It seems that since there's a smaller die size (way over my head), that the cores heat up and cool down rather rapidly.

If that is the case, the fans don't need to stay at the higher rpm for 5 min so a software fix might solve this (guessing)

gee, I LOVE getting all low & techy
 

ayeying

macrumors 601
Dec 5, 2007
4,547
13
Yay Area, CA
soemtimes 5 minutes.. sometimes a few hours. None of my other systems, even an old compaq tablet pc required 5 minutes for no load to cool the system down.
 

thehuhman

macrumors member
Jan 28, 2008
78
0
NC
I have an MBA 1.6/80 which is silent when the fan is 2500. Unfortunately when I do anything that has CPU load above 15% for 30 seconds - 1 minute the fans spin up to 6200 and then stays there for a long time (5 minutes say) before it tries to slow down again (even if the CPU temp is 50-55 again. If I sleep and open again immediately it will usually slow down immediately to 2500. Doesn't matter what I run (videos, Parallels, whatever) if its above 15% or so the fan speeds up.

What I see on the boards are obviously the people who have this problem. What I would like is for all of you that DON'T have this please report in. I'd like to know that there are hundreds of you with OK fan behavior. Then I would know that mine is defective and I would get another. BUT if there is no one out there who doesn't have this issue than why bother to try to return; it's a design issue. I have definitely seen a couple posts where people do exchanges and end up just where they are in the beginning.

Let's hear from all of you WITHOUT fan issues.

I've had mine since Feb 7th, and I use it everyday. I feel like (in that length of time) that I've pretty much run it through the paces, and I have yet to hear the fans. After a couple hours, the bottom does get hot, on the left side, but it NEVER gets as hot as either of my Dell Laptops did.
 

sparkstack

Guest
Feb 19, 2008
36
0
I do not and I've had mine since Feb. 1 so it was a first batch. Fan comes on when it needs to and slows itself down when it needs to.

Usually at 2500 and tops at 6200rpm.

Same here. But then i tend not to block all the air vents by sitting the air on a duvet....
 

AC Rempt

Contributor
Feb 24, 2008
290
19
I have a 1.6/80, and while my fans roared full speed when I was doing the clean install of OS X and a migration from my MB, since I did the COPS reset, it's been dead quiet.

I've tried taxing it via YouTube, and nothing. It's all good.
 

twynne

macrumors 6502a
Apr 21, 2006
805
45
London, UK
I think mine's 'normal' as well. I have a 1.8 SSD model. As a test, I've just tried watching a film with all of the following running:

Parallels (XP Pro inc. IE and Digiguide)
Firefox
Safari (10-15 sites open)
Activity Monitor
Adium

Video playback was using VLC (608x256 @ 24fps).

Video playback was absolutely smooth. Fans started to increase after about 20 minutes of playback as CPU temp reached a max of 60. This gradually cooled back to 54-55 and the fans returned to normal. I assume this pattern would repeat over time.

Seems pretty normal to me.
 

al82

macrumors regular
Feb 13, 2008
201
0
I dont mind the fans kicking in, what annoies my is the computer slows down when it kicks in. Videos become unwatchable no matter how poor the quality.
 

UltraNEO*

macrumors 601
Jun 16, 2007
4,057
16
近畿日本
I have an MBA 1.6/80 which is silent when the fan is 2500. Unfortunately when I do anything that has CPU load above 15% for 30 seconds - 1 minute the fans spin up to 6200 and then stays there for a long time (5 minutes say) before it tries to slow down again (even if the CPU temp is 50-55 again. If I sleep and open again immediately it will usually slow down immediately to 2500. Doesn't matter what I run (videos, Parallels, whatever) if its above 15% or so the fan speeds up.

What I see on the boards are obviously the people who have this problem. What I would like is for all of you that DON'T have this please report in. I'd like to know that there are hundreds of you with OK fan behavior. Then I would know that mine is defective and I would get another. BUT if there is no one out there who doesn't have this issue than why bother to try to return; it's a design issue. I have definitely seen a couple posts where people do exchanges and end up just where they are in the beginning.

Let's hear from all of you WITHOUT fan issues.

If it really bothers you, i guess you could think about
installing a smc fan controller?

http://homepage.mac.com/holtmann/eidac/
 

ctt1wbw

macrumors 68000
Jan 17, 2008
1,730
2
Seaford VA
I have had my Air for about a month or so, and I think I've heard the fan come on once. Granted, I was heavily into some gay porn videos in HDTV, so that might explain it. Once the movie was done, the fan shut off.























:D
 

Scott6666

macrumors 68000
Original poster
Feb 2, 2008
1,511
980
If it really bothers you, i guess you could think about
installing a smc fan controller?

http://homepage.mac.com/holtmann/eidac/

I guess I don't understand how this program would help. It seems to set minimum speed not maximum speed. Making the fan go faster is not a goal of mine. Plus since my MBA is dead silent 70% of the time and only spins up with some cpu usage I don't think that keeping the computer cooler for that 70% of the time will do me any good when the CPU is being used.
 

Scott6666

macrumors 68000
Original poster
Feb 2, 2008
1,511
980
Not consisent so far

This forum is not being as consistent as I would hope.

There do seem to be a small % (say 20%) who seem to say that their's is "quiet as a mouse" or did OK with youtube video.

Most others seem to say that with video as the test the fans speed up. Some say that's "normal" some say not.

So I guess the test case for all is: if you watch a video and istat says your cpu is about 30%, does your fan spin up (a) within a minute a two, (b) within 15-20 minutes, or (c) not at all.

Let's also assume that I consider that fans spinning up to max on 30$ cpu usage should not be "normal" if I were to design a machine. CPU over 70% on a consistent basis (say doing an install) spinning the fans to max would be "normal" in my design IF when the CPU load ceased that the fan would slow down within a minute. Does your MBA meet my definition of normal?
 

Scott6666

macrumors 68000
Original poster
Feb 2, 2008
1,511
980
So you're saying...

I dont mind the fans kicking in, what annoies my is the computer slows down when it kicks in. Videos become unwatchable no matter how poor the quality.

I hear that you don't mind, but how long does it take for your fans to kick in while watching video and does it stay cranked up throughout the video? Does your second core shut down (check the activity monitor)?
 

Phil A.

Moderator emeritus
Apr 2, 2006
5,800
3,100
Shropshire, UK
No problems at all here: Fan normally runs @2,500 RPM. When I put the machine under heavy load, the fan speed gradually increases as the core temp increases but reduces nice and quickly as things calm down.
At the moment, I'm running it plugged into the charger with an external ADC, and a DVD drive, HDD, card reader and iPod all plugged into a USB hub. I'm running Entourage 2008, Safari, iTunes and Word 2008 with MySQL running in the background and everything is nice and quiet: 20% CPU Usage and 2499 RPM.

If I start up VMWare and run Windows 2003 things will get a bit warmer as the CPU usage increases. This means the fan will kick in and gradually increase in speed, but the temperature never "runs away" and I never get a core shutting down. Also, the fan speed decreases as the temperature decreases. It basically works exactly the same as my old MBP did
 

mcvaughan

macrumors 65816
Aug 9, 2007
1,358
980
Houston, TX
No problems at all here: Fan normally runs @2,500 RPM. When I put the machine under heavy load, the fan speed gradually increases as the core temp increases but reduces nice and quickly as things calm down.

I see the same behavior as well. Yesterday I watched several YouTube videos in a row to see if I could get one of my cores to shutdown. My MBA ran as expected and had no problems at all. The fans and temp gradually increased but then calmed down after I finished watching the videos.

Edit: this is on a 1.8/64, FWIW.
 

Stratus Fear

macrumors 6502a
Jan 21, 2008
696
433
Atlanta, GA
If I'm not doing much of anything (Safari, IM, Word, etc.) temps stay in the low to mid 40s with the computer on my lap, fan @ 2500. If I do anything like video, after a few minutes the CPU will get pretty hot and speed the fan up to 6200. If I'm not doing that too long, though, the fan will come back down pretty quickly. If I'm watching a long video or anything intensive for a long period of time (20+ min) it takes the fan a while to come back down, maybe 5-10 minutes. What I did notice, though, is when this is the case, other system temps as measured by Temperature Monitor are also high. The fan isn't just a CPU fan -- it's a system fan. If the system temperature is still a bit high even after the CPU has cooled back down to 50 or so, the fan is still going to run until those other temp sensors are back to a normal range.

I think that some people are forgetting how small these machines are for the amount of heat they can produce under heavy load. The fan is gonna run a while if the overall internal case temperature is high, regardless of the CPU temp -- I think that's what people are actually seeing here, and that's also my experience. But it does that because it's by design. A fan this small also can't move a large amount of air, even at high speed. Just by that, it's going to run a while under certain conditions.

In regards to cores shutting down, I've only noticed one shutting down on mine when the overall system temp was high, not only when the CPU temp was high. The core shutdown isn't just to protect the CPU -- it's to protect the entire internals from too much heat. For example, mine, under some heavy load with some H.264 stuff and a couple other programs would peak as high as 80C on the CPU temp, but the second core didn't shut down until the entire system was running hot. It was pretty happily churning away before hand @ 80C until that happened.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.