2012 MBAs: Battery and heat difference between Ivy Bridge i5 and i7

Discussion in 'MacBook Air' started by Jobsian, Jun 12, 2012.

  1. macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #1
    In the absence of any comprehensive battery and heat benchmarks so far, I was wondering if anyone had any ideas/thoughts on the question.

    Last year's MBA Sandy Bridge i5 and i7 models showed little difference in battery life according to Anandtech, though I can't remember the exact margin. However in terms of heat there were a lot of anecdotes on this forum that the i7's were running hot on idle compared with the i5's (a major turn-off for me).

    Now given this, normally I wouldn't hesitate to get the i5, except for the fact that early benchmarks are showing an even greater performance difference between 2012 11" model i5 Vs 2012 11" model i7, around 25%. For some reason, the geekbench difference between the two 2012 13" models is minuscule (anomalous result?).

    I'm aware that this won't translate into a noticeable difference for everyday performance but I am tempted by this power difference for those times where I will stress the machine (eg video encoding).

    But it depends on heat and battery differences. I've seen conflicting posts on this around the place already and I'm not sure of the technicalities. Intel have confirmed that both the ivy i5 and i7 will run at 14W, but is that necessarily an indication of identical power draw and battery life? And what about heat, anyone know the technical differences as to why the i7s were hotter idle last year and are those differences still present this year?
     
  2. macrumors 65816

    Joined:
    May 4, 2012
    #2
    The short answer is that no one knows until someone does tests. The people on here who claim the I7 uses more power and creates more heat are simply guessing that a faster CPU always does this.
     
  3. macrumors 65816

    Joined:
    May 20, 2008
    #3
    I am also very curious about this. The ivy bridge i5 is faster than last year's i7 so if it is cooler and quieter it seems like the better choice for most users.
     
  4. macrumors 6502

    Joined:
    Sep 14, 2007
    #4
    But you could look at this way

    the i7 gets a task done in 40 seconds at full power and heat

    the i5 gets the same task done in 60 seconds at full power and heat

    The same amount of energy has been used for either, although one pulled more , it did it more quickly. So battery power must be no different.

    Heat on the other hand, id rather have it hot for 40 seconds then 60 seconds if you were protecting the longevity of your kit.
     
  5. thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #5
    Looks like it was a mistake after all, following posted in the news forum:
     
  6. macrumors regular

    Joined:
    Feb 2, 2012
    Location:
    Leuven, Belgium
    #6
    That would be one way to look at it. I think your estimates of battery life are quite accurate, looking at the benchmarks of the previous MBA i5 vs i7. The i7's battery lasted only a little bit shorter.

    What I disagree with, though, is that "short hot heat" bit. What I read in this forum was that several i7 users reported their notebook was quite warm even in idle, whereas the i5 users didn't. Even the slightest hint at this possibility is enough for me to run away screaming. I had one notebook that did this. Heat problems never get better, they degrade over time. I didn't like opening my notebook on a regular basis (say, once a year after the first 2-3 years) to clean up the thermal paste and to replace it with new paste. For that reason, I will never go for a notebook that has reports of being "fairly warm in idle". I don't really need the extra processing power (though it would be nice when I start organising my photo collection shot in RAW). I prefer a laptop that works stably for 5 years or more.

    Just my $0.02, of course.


    Peter.
     
  7. macrumors 6502

    Joined:
    Mar 23, 2009
    #7
    It's pretty widely reported that desktop Ivy chips run quite a bit hotter than Sandy chips, especially when overclocked. No idea if this translates to the mobile variants.
     
  8. thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #8
    Likewise, if there is any idle heat issues I'm steering clear of i7. I don't mind a bit of heat when I'm stressing the thing, but not when I'm reading email.
     
  9. macrumors member

    Joined:
    Nov 17, 2010
    #9
    You guys are seriously making me doubt my choice to purchase the i7 11 inch. Should I consider changing my order?
     
  10. macrumors regular

    Joined:
    Feb 1, 2012
    #10
    If you had gotten a 13", yes (as there is only a very small improvement between the two). However, the 11" is showing upwards of 25% improvement between i5 and i7. I say just get it, and if it feels like it's running too warm for your liking then just take it back.
     
  11. thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #11
    Don't forget that the performance difference between the two processors in the 13" model isn't as small as first thought due to a mistake (see my post above).
     
  12. macrumors regular

    Joined:
    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #12
    I just picked up a 2.0ghz i7 11" MacBook Air tonight at the Apple store. I'm just surfing the web right now and it's been on for a couple of hours already. The unit is barely warm so far and I don't think I've heard the fan yet. Apparently fan is redesigned with some new blade technology that is uber quiet.

    Mighty impressed so far but I can tell you at least for surfing the web, let alone idling, the heat is imperceptible at this point. Haven't tried anything hard core yet though. Cheers!

    James
     
  13. thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #13
    Excellent, thank you, an update of how long the battery approximately lasted for you would be great, as would any other anecdotes.

    Eagerly awaiting some formal benchmarks too. So far the anecdotes for the i7 are more positive than last year, don't want to make my decision just yet though in case the i5 somehow eeks out significantly more battery :D
     
  14. macrumors regular

    Joined:
    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #14
    Can't tell you anything on the battery yet as it will have to go through a few charge cycles first to allow for its maximum capacity. No benchmarks yet other than the SSD. Doing around 410MB/s on writes and 450MB/s on reads. (256GB Samsung SSD) Absolute greased lightening! Battery life "seems" similar to my 2011 11" Air but again, too early to tell until the battery gets conditioned. Cheers!

    James
     
  15. macrumors newbie

    Joined:
    Jun 14, 2012
    #15


    Hey James,
    Does the keyboard between the 2011 11" Air seem similar or different to the keyboard on the 2012 11" Air?
     
  16. macrumors regular

    Joined:
    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #16
    Pretty much virtually identical from what I can tell. Initially I thought the keys might be just a teensy bit stiffer on the new 2012 but it is so slight it can probably be attributed to it just being newer and not broken in yet. Otherwise, they're identical layout, colour, back-lighting, etc.

    J.
     
  17. macrumors member

    Joined:
    Apr 27, 2012
    Location:
    Seattle, WA
    #17
    Apple ships the batteries pre-calibrated...it's unlikely that "conditioning" will lead to any improvement. I was hoping that Ivy Bridge would increase 11" battery, but from reading around the last two days it seems that battery life is pretty much the same (maybe an extra 15-20 minutes from Ivy on average, but nothing spectacular).
     
  18. macrumors newbie

    Joined:
    Jun 14, 2012
    #18
    Good to know. Thanks.
     
  19. macrumors member

    Joined:
    Apr 11, 2012
    Location:
    Finland
    #19
    is MBA really so quiet? no fan making uber noices?
    Ny Toshiba laptop is awful, when i turn it on the fan sounds like hoover...
     
  20. macrumors newbie

    Joined:
    May 25, 2012
    #20
    Is it true that MBA fan does make noise that a great advantage.As i'm having HP G42 it makes a lot of noise and having an i5 processor it runs very slow.
     
  21. macrumors 604

    theSeb

    Joined:
    Aug 10, 2010
    Location:
    Poole, England
    #21
    I would suggest waiting for full reviews of production machines, but you can get a good idea from this preview on Anandtech's website about mobile dual core Ivy Bridge

    http://www.anandtech.com/show/5872/intel-dual-core-ivy-bridge-launch-and-ultrabook-review/7
     
  22. macrumors regular

    Joined:
    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #22
    That hasn't been my experience including my 2011 MBA from last year and every phone I've owned in the last 5+ years. Lithium technology batteries are widely known to require several charge cycles before they reach their maximum potential. It might not make a big difference in runtime but regardless, I still don't count on any battery readings from brand new cells until they've gone through a few cycles. Cheers!

    J.
     
  23. thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #23
    Utterly dying for the Anandtech benchmarks. It seems to be good news so far anecdotally, but would love to see confirmation.

    I'm tempted to go to an Apple store and benchmark one of these things myself for 5 hours :p
     
  24. macrumors 68040

    Joined:
    May 3, 2011
    #24
    This is anecdotal and far from a rigorously tested use, but I got 4:47 out of the 11" MBA (see the 11" MBA thread for usage details). That's not great, but it isn't bad either.
     
  25. thread starter macrumors 6502a

    Jobsian

    Joined:
    Jul 30, 2009
    #25
    Thanks, that's getting close to swaying me.
     

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