Post your temp when 6200RPM starts

Discussion in 'MacBook Air' started by silentio, May 9, 2008.

  1. silentio macrumors newbie

    Joined:
    Mar 28, 2008
    #1
    I saw such a thread for the battery health/cycle, and thought it might be useful for fan speed too. I saw in another thread that MayaTlab's MBA goes crazy only at 70 degrees. Here are my temperatures when my fan starts to spin at 6200

    CPU: 55-60 (my CPU temp hardly ever goes beyond 65)
    Heatsink: 50-53
    Power supply: about 55


    All temperatures in degrees celsius.

    I wish my fans only start going noisy at 70 degrees like MayaTlab, because my CPU hardly goes that hot. My feel is that Apple messed up with the fan control. Hope there'll be another fix for this.

    For those who don't already have it, use the iStat Pro widget to see your temps and fan speed. Rem to switch to degrees celsius
     
  2. ayeying macrumors 601

    ayeying

    Joined:
    Dec 5, 2007
    Location:
    Yay Area, CA
    #2
    +/- 75 deg C before fans goes up. Sometimes 70 deg C (if temps rise slowly)
     
  3. sir. mac macrumors regular

    Joined:
    Nov 21, 2006
    #3
    My MBA 1.6 usually spins up when it gets past 65 d. celsius. But there is a large gap between the measurement on Coolbook and SMCFanControl. Maybe 10 degrees different. Anyone know why they measure different?
     
  4. JAdmiral macrumors member

    Joined:
    Mar 26, 2008
    #4
    67 degrees Celsius @ 6200 rpm.

    Question: How would I know if I'm overheating to the point that a core shuts down? Thanks.
     
  5. silentio thread starter macrumors newbie

    Joined:
    Mar 28, 2008
    #5
    Hmm... not many replies. But here's an update, for the worse. After reinstalling my OS, 6200RPM now starts when my CPU is about 50C. As I'm typing this now, my notebook is running just Adium and this browser window. CPU is 50C, heatsink 49C but fan at maximum.

    This is hopeless.
     
  6. Copperheed macrumors newbie

    Joined:
    May 20, 2008
    #6
    My fan starts kicking in at approx 60 degrees, and often stay there till I have either closed the lid or let it cool down to ≈50 degrees defore it's back at 2500 again.
    Haven't tried fan controll yet, but have returned my first week 12 MBA, and they sent me another week 12, and I think this one is going back as well...
     
  7. MayaTlab macrumors member

    Joined:
    Dec 12, 2007
    #7
    Apple definitely messed up with the fan control system, but don't be too envious of my situation. Yes, the fan begins to accelerate once my CPU has reached 70 degrees, but also when the heatsink has reached 55 degrees. And because the heatsink almost never shoes a difference of more than 10 degrees with the CPU, you can say that the fan starts to accelerate at 63 degrees :).

    Anyway, the colling design of the MBA is terrible (I guess Apple did it to cut costs). My main complain is that Apple could have created a fanless design very easily by using an Ultra Low Voltage processor at 1.2 Ghz and a slightly more advanced heatsink (and also by distancing the chipset from the CPU a little bit more).
     
  8. TheBearman macrumors 6502

    Joined:
    May 23, 2008
    Location:
    Cary, NC
    #8
    Are we missing something?

    I have been following the overheating/fan issue for some time now. I find that there is no real rhyme or reason for the fan kicking up to high speed. I have had it happen with CPU temps as low as 49 and at other times it takes a CPU temp of almost 70. I know from iStat the heatsink normally is 5 to 10 degrees cooler than the CPU. We also have the temps from 6 other locations including the hard drive and power supply. What we don't have is a temp reading of the GPU. I expect it will be within 10 degrees of the heatsink but for now I can only guess. Is it possible that the fans reaching max speed could be the result of the GPU?

    BTW, I have heard two different max fan speeds. For me that number is 6200, I have also heard 6900. Did the fan receive an update at some point that increased it's speed?
     
  9. Stratus Fear macrumors 6502

    Joined:
    Jan 21, 2008
    Location:
    Atlanta, GA
    #9
    The design isn't terrible -- Apple just designed it with different goals in mind than that of other lightweight notebooks. Mainly that of being something better than having a paltry 1.2 GHz processor and not having a thick system enclosure. If you've ever seen the inside of the MBA, you can see that there really isn't any more space for an elaborate cooling system. No way to fit a finned heatsink or heatpipe in there, and that's just the way it is. The main idea of the MBA wasn't to be a "me too" subnotebook and be just like a Sony Vaio or anything like that.

    The fan speed isn't based on CPU temp. It's based on enclosure temp. The fan appears to get going somewhere around 38C or 39C on the #1 and #2 enclosure sensors. If it seems like there has been no pattern to it, that's because people were looking at the wrong sensors :) Also, I think those saying 6900 as the max fan RPM are probably just misstating it. It is definitely 6200.
     
  10. MayaTlab macrumors member

    Joined:
    Dec 12, 2007
    #10
    Unfortunately for Apple, their cooling design transforms the 1.6 Ghz of the MBA into a 1.2 Ghz because it is not efficient enough to maintain a decent temperature on the long run and leads the processor to throttle down. Having made a bunch of HandBrake encodes prior to tunning my MBA, I realized all of them were made at 1.2 Ghz (I never had any core shutdown though). So what's the point in placing a Low Voltage processor (the current processor has a TDP of 20 W) and not an Ultra Low Voltage (which TDP is 10 W) ? Oh yes, as usual : marketing (or perhaps unrealistic dreams ? :)). However; I assume some MBA owners got better made models which succeed in colling efficiently the processor.

    After having replaced the thermal paste, improved the power efficiency of the processor with CoolBook and forced the fan to stay at 2500 rpm after having logged in, my MBA is now perfect, but I am not sure I really enjoyed doing all this. Shouldn't it be already optimized ?

    Don't misunderstand me : the MacBook Air is definitely a great machine and has redefined the way I use my computer (due to its "clever" lack of ports), but I think there is room for improvement.
     
  11. Stratus Fear macrumors 6502

    Joined:
    Jan 21, 2008
    Location:
    Atlanta, GA
    #11
    Ok, but who does Handbrake encodes on what is essentially designed like a subnotebook? Other tasks are going to get a benefit from that processor speed when you're not pushing the machine beyond its limits.

    I think some people's workloads on the MBA are unrealistic. If you want to do Handbrake encodes, you should be using an MBP or an iMac. Me, well I've also fixed the thermal paste issue and I use Coolbook on mine, but I'm also willing to accept that the machine was never designed for heavy workloads in the first place. It still gets hotter than a machine should when doing some heavy stuff, except the MBA was never intended for such things in the first place, so I really have no complaints. I figure that I knew what I was getting into when I bought the MBA, and if I really needed to constantly do heavy workloads on the go instead of on my iMac, I would have bought an MBP.

    But I understand where you're coming from. Improvement would be welcome on the MBA. I'm just saying I think a lot of people are oddly missing what the design goals of the MBA were and thinking that it should be just like an MB or MBP when it most certainly is not meant to be either of those things.
     
  12. MayaTlab macrumors member

    Joined:
    Dec 12, 2007
    #12
    Did I ever complained about the speed of the MBA when encoding? In my post I just said that, in my humble opinion, Apple could have improved the silence of the machine by using an Ultra Low Voltage processor, while keeping most of the MBA initial performances, which is, if I am right, far from asking for a powerhouse. However, you are definitely right when saying that a 1.6 Ghz processor can be an advantage for temporary heavy tasks (but no more than five minutes).

    I don't ask my MBA to be fast but silent. HandBrake encodes can last for more than 12 hours, I just don't care since it is not my main usage (text note, presentations, this kind of very light stuff). Of course, if I could have bought a MBA and another Mac, I would have done so, but that would have been pushing ME beyond my budget limit ;).
     

Share This Page