Core i5 or i7 Retina iMac?

Discussion in 'iMac' started by gadgetgirl85, Jan 8, 2015.

  1. gadgetgirl85 macrumors 68040


    Mar 24, 2006
    I have decided I will upgrade the video card, ram and get the 512 SSD in the retina iMac but am unsure about the processor. I'm not sure whether I'll need the i7? Will be using the retina iMac for word and excel tasks, SPSS, maybe the occasional game or photoshop.
  2. robgendreau macrumors 68040

    Jul 13, 2008
    Sounds like maybe you don't need it. And probably the other priorities are better for your money. Best to check out and see if the software you would use really benefits from the quad processing, and whether some seconds here and there are worth it, especially considering what else you might spend the money on.
  3. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    The i7 is much faster than the i5 when it comes to hyper threaded tasks.

    Photoshop is hyper threaded.

    Even in single core tasks, the i7 will still be a tad bit faster.

    Since you're already upgrading so much, top it off with an i7 to make it a complete package.

    But I wouldn't upgrade the RAM. I'd do the upgrade myself considering how daft Apple's pricing is.
  4. ixxx69 macrumors 65816

    Jul 31, 2009
    United States
    If cost is a concern, the i5 will be more than enough for your needs. If the extra cost isn't a big deal, get the i7 - it's a little faster, though by the sound of it, you probably wouldn't notice anyway.

    Only a few advanced features of PS are multi-threaded. For general use (i.e. editing and touching up photos), the hyper-threading feature of the i7 won't make PS any faster.
  5. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    But considering that she's already selected the upgraded GPU plus a 512GB SSD, why not throw in an i7 to make it an almost maxed-out iMac? Plus it could also increase the resale value.
  6. ixxx69 macrumors 65816

    Jul 31, 2009
    United States
    Uh, I didn't recommend not to get the i7. Personally, I would... but I'm a power user and I can afford it. But there's no reason she needs an i7 for the reasons you stated.

    And resale value is probably the absolute worst reason to get an upgrade like that. Spend an additional US$250 now so that ~4 years from now, she can get an extra $100 for it on ebay? :rolleyes:
  7. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Still better than nothing. Besides, there's no telling where she might need an extra 4 threads down the road.

    Better to spend more initially than to realize that further down the road, when you need more resources, you realize that you don't have the extra threads.
  8. Cape Dave macrumors 68000

    Nov 16, 2012
    I wanted to get the i7. I really did. It is my nature. I love SPEED. However, I wanted to hedge my bets on what I thought could be some heat issues at some point and got the i5.

    Heat/noise not an issue.

    For what I do, it is just fine. Light Photoshop and watching YouTube is about the most strain I will put on the CPU/GPU :)
  9. Sirmausalot macrumors 6502a


    Sep 1, 2007
    Hold off on the RAM upgrade completely and get the i7. You'll find you can do plenty with an SSD and 8GB RAM. Then upgrade the RAM later as a present. You might not need the i7 power now, but you'll both appreciate it now and you will certainly want it somewhere down the road!
  10. T'hain Esh Kelch macrumors 601

    T'hain Esh Kelch

    Aug 5, 2001
    If you plan to do Photoshop *a lot* get the i7, otherwise, stay with the i5. It won't give you any advantage in all the other tasks you listed.
  11. joema2 macrumors 68000


    Sep 3, 2013
    I know you probably didn't mean it this way and were just speaking in "shorthand", but for the benefit of others: there are no "hyper-threaded tasks" per se. Rather there are only multi-threaded tasks, which may or may not benefit from hyperthreading. In general the programmer has little control over this. There is no hyperthreading API or special instruction set like with Quick Sync or AVX instructions. It just happens or doesn't -- totally up to the CPU.

    Most apps are heavily multithreaded. Just opening Safari produces about 24 threads. However this does not automatically mean a hyper-threaded CPU will speed up Safari, since most of those threads are not in a runnable state, but waiting on I/O, or a synchronization event. However any app with multiple threads in a runnable state are potential candidates for hyper-threading.

    The OS X thread dispatcher is hyper-thread aware and will often schedule a thread per physical core (rather than a thread per logical core) if it judges that more efficient. This can be seen in Activity Monitor when every other logical core is scheduled.

    Narrow sections of Photoshop can benefit from hyperthreading. Lightroom import/export does not benefit at all. FCP X export benefits significantly -- about 30% faster. The only way to know for sure is run the task on an i7 iMac with HT on and off. Turning off HT requires the CPUSetter utility:

    While there are no "hyper-threaded apps" per se, developers can use various techniques to make their apps better behave
    on a hyper-threaded CPU. Intel has guidelines on this in their whitepaper "Developing Multithreaded Applications: A Platform Consistent Approach":,d.eXY

    Re the OP question I don't see an i7 making a huge improvement. However with the i7 retina iMac you also get a 14% clock speed improvement which will help almost all apps -- if you need that.
  12. hologram macrumors 6502

    May 12, 2007
    Absolutely. I just got the i7 even though I don't really need it at the moment, but I don't want to regret it a couple of years from now. I'm not one of the lucky ones who get to replace their computer every year or two, and the extra expense now is a small price to pay for a certain amount of future-proofing.

    And I imagine more and more games will be multi-threaded-capable in the near future, too.
  13. cynics macrumors G4

    Jan 8, 2012
    Aside from very specific applications I generally find (with real world timed benchmarks) a CPU upgrade to be the least bang for the buck upgrade. That SSD is going to make the biggest difference and is a worthy upgrade.

    That said as others have mentioned if money isn't tight go for the i7 it is technically better and likely to be more future proofed.

    I have an i5 and the most CPU intensive thing I do is Handbrake. Compared to my friends retina i7 I'm not overly impressed with his Handbrake run times. I feel they are better but nothing that I would say "I have to upgrade!!". For my uses as of today I can't justify the price vs performance (that may change in the future).

    All that said my next iMac will be maxed out assuming I'm satisfied with customer feedback (noise, heat, etc).

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