iMac - i5 or i7?

Discussion in 'iMac' started by doubleohseven, Sep 16, 2011.

  1. doubleohseven macrumors 6502a

    doubleohseven

    Joined:
    Jan 13, 2008
    Location:
    Sydney, Australia
    #1
    Hi all,

    I am looking at purchasing a 21.5" iMac around December this year/early next. While the current models are tempting, I intend to hang around for an i7 21.5" model. Although ultimately, what are the major differences between i5 and i7, other than it being a faster processor (I assume?)

    I intend to upgrade RAM to 8GB as well as purchase a 1-1.5TB External HDD for back ups.

    Thanks!
     
  2. Grumbles Guest

    Joined:
    Aug 2, 2011
    #2
    Since you have to purchase the high-end 21.5" to have the i7 option, you will already have the upgraded video card (Radeon 6770m) and 1TB hard drive included. The only significant difference will be in applications that take advantage of the additional four threads (i.e. mostly video encoding and other professional content apps) while you will see little benefit in everyday usage. Whether the i7 is worth it or not really depends on what you plan to use it for.
     
  3. doubleohseven thread starter macrumors 6502a

    doubleohseven

    Joined:
    Jan 13, 2008
    Location:
    Sydney, Australia
    #3
    Mainly Photoshop, programming (Xcode, maybe Visual Basic if I partition Windows on it) and the odd video editing every now and then. Worth going to i7?

    Also...any rumors about BlueRay coming to Mac? (Sorry, I haven't been on MR lately). :eek:
     
  4. bniu macrumors 6502a

    Joined:
    Mar 21, 2010
    #4
    I'd go i7, 8 threads vs 4 threads. You can attach a blu ray drive to an iMac if you want and use a third party utility to rip it and then watch it afterwards that way if you want...
     
  5. Trudy macrumors regular

    Joined:
    Sep 30, 2004
    #5
    As of Sandy Bridge (the current generation):

    • i7 hyperthreads (two threads per core), i5 does not
    • i7 has more L3 cache per core, 2-4 MB vs 1.5 MB
    So unless you do a lot of multi-threaded apps and stuff that will thrash the cache, an i7 at the same clock speed isn't going to do much for you over an i5, especially considering the price difference.

    Later this year the i7 will get QuickPath Interconnects back instead of the slower Direct Media Interface, and the RAM will go from two channels to four. This should widen the difference between the two.
     
  6. marioman38 macrumors 6502a

    marioman38

    Joined:
    Aug 8, 2006
    Location:
    Elk Grove, CA
    #6
    One factor is consider in choosing a Mac is cost/performance equation. For example, the base 3.1GHz Core i5 (27") iMac costs 18% more than the 2.7GHz Core i5 (27")iMac . When rendering a project in After Effects, the 3.1GHz iMac is 10% faster. When running the iTunes conversion, the 2.7GHz iMac is 8% faster. If you stop there, the 2.7GHz Core i5 appears to have the best bang for the buck. But if you are a gamer, the 3.1GHz Core i5 (with Radeon 6870M) is as much as 87% faster than the 2.7GHz Core i5 (with Radeon 6770M) running games like Portal 2. That's why when readers ask me for purchase advice, I respond with the question, "What are the three most demanding apps you run?"

    Here is a link with performance of i5 vs i7 iMac http://barefeats.com/imac11f.html
     
  7. 3083joe macrumors newbie

    Joined:
    Dec 25, 2012
    #7
    Thnks for that, I do lots of short 2 -10 min videos with average effects with premiere and after effect cs6 would it be worth the money to go to the i7 over the i5?
    TIA
     
  8. eternalife macrumors regular

    Joined:
    Jul 21, 2011
    #8
    Same (or similar) question here. I will be using FCP (overkill but wanting to learn it) for 2-10 min HD family videos with average effects. I also use CS6 and Lightroom. Will the i7 present a noticeable improvement?
     
  9. marioman38 macrumors 6502a

    marioman38

    Joined:
    Aug 8, 2006
    Location:
    Elk Grove, CA
    #9
    Unless you guys are getting paid for your work, the difference in speed is negligible. The i5 is so fast these days its not really necessary for an i7. I have an i7 in my desktop and have only used its potential 1 or 2 times in the past 6 months, I only got it because the i7 package deal happened to be on sale cheaper than the i5... The i5 1.7ghz dual core (not quad) in my Macbook Air is plenty fast for Lightroom and Photoshop. Encoding videos is where you'll notice a difference, but its not hard to just click encode, and go to bed while it works overnight. Or if its an hour or two leave the room and take care of something else that needs done.
     

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