Why does RMBP CPU scale so poorly compared to MBA?

Discussion in 'MacBook Pro' started by macbook123, Jun 13, 2012.

  1. macbook123 macrumors 68000

    Feb 11, 2006
    I ordered a base RMBP right after the announcement, as I've been longing for an IPS panel in a Mac laptop, but am having second thoughts. Geekbench scores see it only 50% faster than the top level MBA, at 10800 versus 7000. On the other hand, the RMBP is 50% heavier and bulkier. Do people know why the 4x2.3 GHz in the RMBP is only 50% better than 2x2.0 GHz in the MBA?

    Anyway, I'm reconsidering my purchase, given that I could get a top of line MBA WITH 512 GB SSD for the same price as this 256 GB RMBP. I just wish the Air had an IPS panel in it (high res is less important for me personally).
  2. Mr MM macrumors 65816

    Mr MM

    Jun 29, 2011
    well you have answered the question yourself, since 50% of more performance is not important to you, get the air
  3. dccorona macrumors 68020


    Jun 12, 2008
    the processor is a positive to the rating, but theres also the negative hit of the much higher resolution display. Yes, most of this is handled by the graphics card...but not all of it. That brings the performance back down. And remember, anything that uses only a single core will essentially be 2.0 vs 2.3...the advantages of the macbook pro won't really show themselves until turboboost gets running and those extra cores become needed by an application
  4. TheMacBookPro macrumors 68020


    May 9, 2008
  5. Dangerous Theory macrumors 68000

    Jul 28, 2011
    Not to mention he's not even fussed about its main selling feature. Sounds like an air is the way to go, if 13" display is big enough.
  6. macbook123 thread starter macrumors 68000

    Feb 11, 2006
    That doesn't answer my question, which is "Why does the RMBP CPU scale so poorly compared to the MBA?"


    You're misunderstanding, and sorry if I'm giving the wrong impression. I think both are great. The main reason I ordered the MBP is the display, but I'm still trying to understand why the extra oomph doesn't give the improvements in computing power I would expect.


    So are you saying that these situations are not explored by the Geekbench testing?
  7. mark28 macrumors 68000

    Jan 29, 2010
    It's a synthetic benchmark. Wait for real world benchmarks.
  8. jim468 macrumors regular

    Jun 14, 2009
    Regarding the CPU scaling, the performance improvement by RMBP over MBA will be more easily noticeable when they are benchmarked using application which require more than 2 cores, for example video/audio editing. It can be likely that these situations may not be well explored by Geekbench.

    The biggest benefit of the RMBP over MBA (other than the Retina display) is the dedicated GPU, whose importance cannot be neglected. Especially now, since almost everything UI requires can benefit from hardware acceleration.

    I own a 2011 MBA and I will be upgrading to a RMBP because the lack of GPU in MBA is easily noticeable when you try watch HD movies or connect external displays to it.

    Having a slower CPU will make some things slower like loading webpages, or installing software, etc. But having a slow or no dedicated GPU will make tasks like watching movies, or scrolling webpages jerky, which is much more easily noticeable and frustrating.

    So, I would say that you are paying more for the GPU and Retina display rather than the CPU increase.
  9. macbook123 thread starter macrumors 68000

    Feb 11, 2006
    Very interesting. I'm unable to watch HD movies of any sort (whether stored on my Air directly, or streaming from YouTube) on my 30" HP 2560x1600 monitor with the Air. It would be great if that would work better with the RMBP.

  10. 88 King macrumors 6502

    88 King

    Jun 18, 2011
    London, UK
    I'd suggest looking at review of some Windows laptop uses the same two CPU, as Windows have much better benchmarking tools.

    It always come down to do you need the extra processing power of full powered quad core mobile processor vs dual core running on reduced speed and power.

    I'd imaging transcoding and converting videos will see much more than 50% increase between those two processors.
  11. jim468 macrumors regular

    Jun 14, 2009
    I am guessing it would. Right now I am constantly hitting the 4GB RAM limit on my MBA and since there is no dedicated GPU in MBA, the video memory is shared from the system RAM. So, the more applications I have running, the more slow my UI gets.

    Moreover, regarding watching HD movies on my 1080p external display. They are jerky if my MBA's display is enabled. So I usually turn off my MBA's internal display before I begin watching my HD content. It's frustrating, but there's no way around to it that I know of.

    The 650M is not a "bad" graphics card so I am guessing that it should be able to at least play HD content on multiple displays.

    Regarding Intel's integrated GPU, I would rate it as beyond rubbish. Apple's website says that it's 60% faster. I have fallen for this kind of marketing once (when I bought my MBA) and will not fall for this again.

    I have learnt that nothing can replace a dedicated GPU, even a bad dedicated GPU is better than Intel's integrated GPU.
  12. Mr MM, Jun 13, 2012
    Last edited: Jun 13, 2012

    Mr MM macrumors 65816

    Mr MM

    Jun 29, 2011
    I only stated that if a 50% difference in processing power (which is in fact much more) aint relevant for you, thus you are wondering if you want to go for a mba, you arent going to need it.

    The ulv processors today are much more functional than the ones that came up until the 2011 mba, for most people its quite enough, even for running a VM is enough.

    Playback is smooth on those chips, its a problem with flash that doesnt work right usually. For example the HD 4000 supports 4k screens, and simply this is much more than what is available for people to buy on single monitors. Another thing I never encountered a problem with my early 2011 mbp 13, granted the HD 3000 is clocked higher in my cpu, however I dont see it pushing anything in terms of transcoding or anything. Even driving 1440p res monitors out there.
  13. macbook123 thread starter macrumors 68000

    Feb 11, 2006
    Unfortunately I have been unable to put my internal display to sleep when an external one is attached on my 2011 i7 Air for the last couple of months, due to a software bug in OS X.


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