i7-4558U on 13" rMBP

Discussion in 'MacBook Pro' started by Breedlove, Oct 23, 2013.

  1. Breedlove macrumors regular

    Oct 23, 2006
    Already decided to buy the new 13" rMBP with 16GB and the 256GB hard drive.

    But now I'm having trouble deciding on the processor.

    Is the i7 upgrade worth it?
    With my student discount it is $270 more than the base i5-4238U (2.4gHz).

    My concern is that the base processor will still struggle to power the Retina display, even with the upgrade to Haswell.

    Are my worries unfounded?
  2. teotuf macrumors member

    Jan 24, 2012
    If your worry is powering the retina display, then you shouldn't worry. There are plenty of ultrabooks running on HD4400 15W cpus driving WQHD screens, and they work perfectly fine without lagging.

    The upgrade to the 2.6ghz for $100 might be worth looking at if you are REALLY worried. $200 more on top of that for a measly 5% gain isn't worth it 99.9% of the cases - not to mention you would likely see somewhere around a 10% decrease in battery life given the same workload.
  3. Breedlove thread starter macrumors regular

    Oct 23, 2006
    What about future proofing?

    I'm currently using a fully upgraded early-2009 17in MBP and I already feel it lagging a little.
  4. PDFierro macrumors 68040

    Sep 8, 2009
    The i5 will be plenty fast enough. Although I went with the i7 but 8GB RAM, and I'm happy with that.
  5. teotuf macrumors member

    Jan 24, 2012
    Going from the i5 2.6ghz to i7 2.8ghz you'd see about 5-10% performance increase. You tell me if that's enough future proofing for you.
  6. Breedlove thread starter macrumors regular

    Oct 23, 2006
    How is it just a 5% performance increase?
    Don't we have to consider the increased GPU clock speeds and the 1MB L3 Cache increase?

    What about hyperthreading? Do they both have it or just the i7?
  7. teotuf macrumors member

    Jan 24, 2012
    There are 3 cpus available - i5-4258U at 2.4ghz (1100mhz for gfx), i5-4288U at 2.6ghz (1200mhz), and i7-4558U at 2.8ghz (1200mhz). Going from the base 2.4ghz to i7 2.8ghz for $300, you would see about a 20% increase in performance. Going from the middle 2.6ghz to 2.8ghz, you would see about a 5-10% (and no increase in gfx performance). There is a difference in L3 cache from 3 to 4mb. But unless you specifically know what you need the L3 cache for, you won't even know it's there.

    All of these have hyperthreading/turbo boost/etc/etc/etc all that marketing crap.

    Here are some geekbench 3 scores if you want:
    - i5-4258U @ 2.4 GHz: Single-Core 2613, Multi-Core 5248
    - i5-4288U @ 2.6 GHz: Single-Core 2856, Multi-Core 5954
    - i7-4558U @ 2.8 GHz: Single-Core 3000, Multi-Core 6189
  8. Breedlove thread starter macrumors regular

    Oct 23, 2006
    It seems as more results are coming in that these numbers are becoming less accurate.
    E.g. the base i5-4258U seems to be more accurately coming in at ~2700/~5620.
    Which seems to show that the performance gain from upgrading to the faster i5 is closer to 5% to 6% and not 20% as originally expected.

  9. teotuf macrumors member

    Jan 24, 2012
    That should be a good thing for people buying the base 2.4ghz models. However, going from the 2.4ghz to 2.6ghz you also get an increase to 1200mhz turbo for integrated graphics. And it's a $100 upgrade vs the $200 upgrade from that to i7 (both giving 5% increase in performance over the tier below).

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