21.5" 2011 iMac CPU upgrade? i7 2600s vs i7 3770s?

Discussion in 'iMac' started by tanker5, May 11, 2013.

  1. tanker5 macrumors member

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    Hoboken
    #1
    Has anyone successfully tried to upgrade the CPU in a 2011 21.5" iMac? Mine was shipped with an i5 2400s CPU. I was thinking of upgrading it to an i7 2600s (which is the processor that shipped with the build to order 2011 iMacs).

    However, after doing some research, I found out that the ivy bridge processors and sandy bridge processors use the same CPU socket. So, in theory, the 3770s should be compatible with the 2011 iMac logic board. The two processors are roughly the same price, so I think the 3770s is the way to go -- more performance for my money. It also uses about the same wattage as the 2400s and 2600s, so there should not be a power issue.

    I know there might be some drivers that might need updating. In the 10.7.4 update, OS X added support for ivy bridge processors and HD 4000 graphics. So, IF OS X can be run successfully after upgrading the CPU to the 3770s, I believe that as long as the computer is at least running 10.7.4 (which added support for ivy bridge processors) it should be fine. Since my iMac is currently running 10.8.3, all of the required drivers should be built into the OS.

    Oh -- and I am fully aware that this would void the warranty. The computer is over 1 year old now, and since I do not have AppleCare, there is no warranty anymore on it.

    If anyone out there has any suggestions for me, or any reason they believe I'm wrong, please let me know. I'll reply in the next few days after I make my decision on what I'm going to do. Any help is greatly appreciated.
     
  2. Bear macrumors G3

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    #2
    What about the compatibility of the support chipset in your iMac and the processor you are looking at? Also if it is compatible, will OS X work with that combination.
     
  3. tanker5 thread starter macrumors member

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    #3
    I believe that the chipsets are compatible. But I can't find a definite answer online, just conflicting reports. However, I think any hardware compatibility issues would be fixed by the updates in OS X 10.7.4 and later.

    There might only be one way to find out for sure though...
     
  4. thekev macrumors 604

    thekev

    Joined:
    Aug 5, 2010
    #4
    Well the Sandy to Sandy upgrades seems absolutely pointless. There isn't an appreciable difference between the models used in the 21.5" models. If one isn't up to the task, you are likely to be unsatisfied with the other. The ivy one you quoted is still a jump of 12W maximum tdp, and I'm not sure how hot one runs compared to the other in actual use, or if the board firmware works properly. The 3770 would give you an increase in performance if you are currently cpu bound. These things are often more commonly upgraded with mac pros because of the stratification within the E/EP cpus and greater year to year consistency between chipsets. For a lot of people the proposed upgrade wouldn't extend the useful life of that machine by one day. If it's lagging on something I understand. Otherwise it may not be worthwhile unless something cpu bound is a bit laggy today. With most of these things you won't know if it will work properly (without kernel panics or other issues) until you try it.
     
  5. tanker5 thread starter macrumors member

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    #5
    It's true that there is not much of a difference between the i7 2600s and the i7 3770s. BUT -- Since my iMac currently has the i5 2500s (by the way - earlier in the post I accidentally stated that the current CPU is the 2400s - It's the 2500s), either the 2600s or 3770s would be a noticeable performance upgrade.

    The 3770s has the same wattage as the 2600s (65 watts). the 3770 and 3770k are 12 watts higher.

    Even the 2500s to the 2600s would be worthwhile to me because I would be going from a quad core i5 to a quad core i7 with hyper threading (8 virtual cores clocked at 2.8 GHz vs 4 cores at 2.7 GHz).

    The i7 3770s is selling for around $300, while the 2600s is selling for about $330. So, the 3770s seems like a better deal because it's cheaper and has higher benchmarks.

    Also, the Ivy Bridge processors support the z68 chipset which is the chipset on the 2011 iMac logic boards.

    If it's possible to get the performance of a 2012 iMac with my 2011 iMac, I think it would be a worthwhile upgrade.
     
  6. Bear macrumors G3

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    #6
    OS X may not support the combination. Remember, if it's something Apple doesn't sell they haven't tested against that combination, so they would not fix issues around it. Apple already has enough systems they need to test OS X with.
     
  7. Obioban macrumors regular

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    Oct 19, 2011
    #7
    Please post your results, I've very interested in this-- have been contemplating the same process.
     
  8. tanker5 thread starter macrumors member

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    Hoboken
    #8
    Well, I've decided to give it a shot and see what happens. I'm prepared to suffer the consequences if I don't succeed. I have the 3770s on order and it should be here later on in the week. Unfortunately, because of my hectic work schedule, I might not have a chance to sit down and do the swap for another week or so. I will keep you posted on my progress.
     
  9. Obioban macrumors regular

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    Oct 19, 2011
    #9
    Can't wait :D
     
  10. tanker5 thread starter macrumors member

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    Apr 19, 2011
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    Hoboken
    #10
    Update -- i7 3770s NOT compatible

    Well, I have been going at this all day. I have dis-assembled and reassembled my 2011 21.5" iMac about a dozen times. I have gone through almost 2 full tubes of thermal paste. No matter what I do, the computer will not boot with the Ivy Bridge processor. It's not a total loss though. I learned a lot about the internal components of the iMac, and was able to also install dual SSDs in a RAID 0 configuration (thanks to OWC's special kits for replacing the HDD temperature sensor cable in the 2011 iMac and adding a second drive to the 2011 iMac -- Links below). I plan on using the ivy bridge processor I purchased for a hackintosh build. All in all, I look at it as a learning experience. My computer is back up and running with the original 2500s cpu. I plan on swapping it out with a 2600s eventually.

    OWC kit for replacing original HD in a 2011 iMac:

    http://eshop.macsales.com/item/Other World Computing/DIYIM21HDD11/

    OWC kit for adding a second drive in the 2011 iMac:

    http://eshop.macsales.com/item/OWC/DIYIM21SSD11/
     
  11. MacMike1971 macrumors newbie

    Joined:
    Oct 28, 2015
    Location:
    UK
    #12

    Thanks for your perseverance but sorry it didn't work.

    The reason is that it requires EFI BIOS, or whatever the Mac equivalent is of BIOS.

    I tried to upgrade a Gigabte z68 chipset ATX motherboard with a 2500k to a 3550 CPU and it wouldn't boot with the IvyBridge CPU. Put the 2500k back in, boot's no problem. The GigaByte's board can be updated to EFI BIOS but I tried that without success. The socket is the same for 2nd and 3rd gen Intel CPU's (LGA1155), but it's just the EFI bit that's needed.

    Looks like my 2011 iMac is staying with the 2500s CPU...

    Hope this helps.
     

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