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iMac advice

291 Views 11 Replies Latest reply: Feb 20, 2013 12:14 PM by Eleonora. RSS
Eleonora. Calculating status...
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Feb 20, 2013 9:07 AM

To replace my (very) old Mac Pro*, I'm looking into buying a second hand iMac. I will use it voor video editing, always updating to the latest software versions, so it's very important to find the right one. I still don't understand the difference between some iMacs though.


I need a 27" screen and a machine that can do 64bit, so that's important. Other than that I've got some questions:


  1. What's the difference between the i3, i5 and i7? It doesn't seem related to the processor speed when I look at all the different ads. What's more important? I'm used to 2x 2.66GHz at the moment.
  2. I understand that RAM is upgradable, the processor is not, and what about the HD?
  3. Any other advice?


I'm probably the 1000th person to ask this kind of question, but I could really use some help! Thanks very much in advance.




*Specs of my current Mac: 2 x 2,66 GHz Dual-Core Intel Xeon, 5 GB 667 MHz DDR2 FB-DIMM, ATI Radeon X1900 XT 512 MB

Mac Pro, Mac OS X (10.5.8)
  • Mike Sombrio Level 6 Level 6 (9,070 points)
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    Feb 20, 2013 9:54 AM (in response to Eleonora.)

    Eleonora, If I were you I would only consider buying a refurbished iMac from Apple. They come with a full one year warranty and you can purchase AppleCare reasonably to extend the factory warranty out to 3 years. Ram is fully upgradable to as much as 32Gb depending on which model you buy. The hard drives are standard SATA drives but require a lot of work to replace and have integrated temperature sensors so buying the exact make and series is critical. It's best to buy a large enough hard drive to start and then add externals to increase your storage. Upgrading an iMac isn't nearly as easy as with a Mac Pro but the factory specs and built in displays are pretty impressive. Take a look at the current offerings at Apple's online store.

  • Mike Sombrio Level 6 Level 6 (9,070 points)
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    Feb 20, 2013 11:14 AM (in response to Eleonora.)

    Google is your friend. I searched "compare i5 to i7". Here's just one article,2817,2404674,00.asp

  • Mike Sombrio Level 6 Level 6 (9,070 points)
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    Feb 20, 2013 11:15 AM (in response to Eleonora.)

    A quad core i5 and for sure a quad core i7 imac with lots of ram will blow your existing Mac Pro away.

  • MichelPM Level 5 Level 5 (7,125 points)
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    Feb 20, 2013 11:35 AM (in response to Eleonora.)

    Hi Eleonora!

    Welcome to the Apple Community Forums!


    First issue I'd like to address is the purchase of the used iMac, itself. If you do not think that you can afford an older iMac out of Apple's own refurbished section, then you need to search out an Authorized Apple Reseller/repair center for your used iMac purchase. Stay away from eBay as the Macs sold ther may look like a deal, but you maybe, in fact, inheriting somebody else's problems and issues. If the seller is not willing to refund your money and can return the Mac, you are left with  a Mac that now you need to get repaired before you can even attempt to use it! Also, eBay seller do not have warranty plans. So, you would be out of luck for any type of warranty protection.

    Authorized Apple Resellers, if they are very reputable and well established as good, honest Mac resellers will have an initial warranty period with, perhaps, the option for purchasing a limited extended warranty period.

    Most reputable Mac resellers will have a stated warranty anywhere from 30 days to 90 days with, perhaps, a purchased warranty plan that may cover the used Mac for six months to one-year.

    I purchased my used iMac the a reputable Mac reseller and was able to a six month warranty.

    That's a pretty good warranty on a Mac that was three years old.

    So, that's my advice on where and where not to purchase used Macs.


    The 27 inch screen model iMacs started in late 2009. So , I would look at 27 inch screen iMac models between late 2009 and early to mid 2012.

    The i3, i5 and i7 designations of Intel CPU's refers, basically, to the numbers of Cores that each CPU type has.

    i3 chips only have two cores or "dual" cores and are Intel's slowest CPU types.

    The i5 and i7 Intel CPU chips have four cores or "quad" cores in them.

    The difference between the i5 and i7 CPUs is that the i7 have something called true multi-core hyper threading.

    The i5 CPU chips do not have this capability.

    This makes the i7 CPUs much faster than the i5 CPU's and, in turn, make the i5 CPUs faster than the i3 CPU chips.

    So, that is it in a small nutshell.


    iMacs only have user upgradeable RAM.

    There are no other components that can be upgraded.

    So, you can't easily break into an iMac and upgrade the hard drive.

    And you can't at all replace the CPU or GPU (Graphics processor).


    Since you work with video, you need to find a used 27 inch screen model iMac that uses an i7 CPU.

    This is the best and ideal CPU for video work.

    You might be able to get by with an i5 CPU as long as it is the fastest i5 CPU that was available in an iMac.

    You will also need a relatively fast GPU.

    Look for a 27 inch screen model that also has a GPU with, at least, 1 GB of VRAM.

    GPU with 512 MBs of VRAM won't be fast enough for video work.

    Also, decide on what you need for a internal hard drive size.

    2009 iMac models and up come with, at least a 1 TB drive.

    There are options where iMacs have 2 and 3 TB drives installed.

    Good Luck in finding the right used iMac for you!

  • MichelPM Level 5 Level 5 (7,125 points)
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    Feb 20, 2013 12:00 PM (in response to Eleonora.)

    The 2011/2012 i5 Fastest CPU are either 3.1 Ghz or 3.2 Ghz speeds.

  • MichelPM Level 5 Level 5 (7,125 points)
    Currently Being Moderated
    Feb 20, 2013 12:15 PM (in response to Eleonora.)


    Actually i3 CPUs can come in the same ranges as the i5 line of CPUs.

    The difference is the i3 is only a Dual core CPU.

    i5 CPUs are quad core and should say whether they are dual or quad core CPUs.


    Message was edited by: MichelPM


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