Can I use an Intel "K" processor in late 2013 Haswell iMac?

Discussion in 'iMac' started by CompanionCube, Nov 20, 2013.

  1. CompanionCube macrumors regular

    CompanionCube

    Joined:
    Aug 3, 2009
    #1
    I'll be opening up my brand new i5 2013 iMac to upgrade the CPU to a new 4770 i7, and I am wondering if I can use a 4770K or if it has to be a locked 4770 CPU.

    Anyone know if that matters at all?
     
  2. yjchua95 macrumors 604

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    #2
    In the 21.5" Haswell iMac, the CPU is soldered. So you can forget about doing that on a 21.5".

    In the 27" Haswell iMac, you can replace the CPU easily. However, I'm not sure whether you can over clock the i7-4770K in the 27" iMac or not (via Windows n Boot Camp).

    The i7 used in the 27" iMac is the i7-4771 (performance wise, it's the same as the 4770K minus the unlocked overclocking part)
     
  3. CompanionCube thread starter macrumors regular

    CompanionCube

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    Aug 3, 2009
    #3
    Got it! I will make sure to order the same i7-4771 processor then. I have a 27" iMac Haswell that I will be opening up. This post helped immensely thank you sir.
     
  4. paukivbashne macrumors member

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    Ukraine
    #4
    has anyone actually tried this yet?
    i just did and it won't start
    i tried i5 the one I'm replacing( in case i did something wrong while disassembling even though its not my first or second time)and it worked but the i7 -4771 just won't start ?? any ideas (except for the defected processor of course)
     
  5. IA64 macrumors 6502

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    Nov 8, 2013
    #5
    Have you tried resetting the logic board? and that SMC reset also.

    Btw, what do you mean by " it won't start" ? do you hear the chime ?
     
  6. Idarzoid macrumors 6502

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    Mar 15, 2013
    #6
    I wonder if the mainboard is programmed not to accept any CPUs other than the ones it can be configured with or even maybe the one it was shipped with? It's a possibility.
     
  7. IA64 macrumors 6502

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    Nov 8, 2013
    #7
    Some people had successfully swapped the CPU on the iMacs. Others could not.

    The new processor physically fits fine but the computer wont boot with the new chip. They tried swapping the CPUs back and forth a couple of times just in case they missed anything but each time the i7 CPU failed to boot.

    They suggested there are one of three possibilities:

    1 - Apple have restricted the logicboard firmware to specific CPUs.

    2- There is not enough power for the i7 (95W as opposed to 74W).

    3 - The logicboard requires the graphics capabilities of the FCLGA 1156 Socket chips.

    Additional readers -- in particular the very helpful Andy Hucko of Bratislava, Slovakia -- were able to confirm that there are not logicboard firmware restrictions, and the above upgrade was restricted only by power, or specifically, the TDP (Thermal Design Power), which refers to the heat dissipation capability of a particular CPU cooling system.

    Long story short... thankfully there are not restrictions on processor upgrades in firmware for any of the Aluminum iMac models.

    However, one only can upgrade the processor in an Aluminum iMac with a socket-compatible processor that has the same, or lower, TDP as the originally installed processor.
     
  8. CompanionCube thread starter macrumors regular

    CompanionCube

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    Aug 3, 2009
    #8
    Well it's all done!! Upgraded my i5 4670 to an i7 4771 flawlessly! It was tricky messing with the CPU/GPU cooler. Tightening the CPU retention clip was tricky.

    Otherwise it was smooth and much easier than my 2009 iMac. The tools and foam strips that iFixit supplies are perfect fit. :D
     
  9. yjchua95 macrumors 604

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    #9
    'Grats mate!
     
  10. CompanionCube thread starter macrumors regular

    CompanionCube

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    Aug 3, 2009
  11. richard13 macrumors 6502a

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    Mill Creek, WA
    #11
    I'm confused, why didn't you just order your new iMac with an i7 processor? Am I missing something?
     
  12. CompanionCube thread starter macrumors regular

    CompanionCube

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    Aug 3, 2009
    #12
    It was a gift so I couldn't choose what I wanted to order with it. :)

    Plus it's fun to open them up and mod them.
     
  13. paukivbashne macrumors member

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    Ukraine
    #13
    false alarm fellas
    just a defected processor :D
    So its been tested and I'm confirming that i7 -4771 (not k or s or whatever)
    is indeed working and compatible and this machine is a monster now :)
     
  14. nateo200 macrumors 68030

    nateo200

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    Northern District NY
    #14
    Wow thats pretty awesome that you can do this. Just curious is the processor you put in more powerful than any of the options Apple has for the i7 upgrades on the iMac? I haven't checked Intels website lately and dug through the processors in the iMacs....I think if the power/thermal limitation wasn't in place I would go ahead and throw in a 6-core i7 and overclock it :D
     
  15. yjchua95 macrumors 604

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    #15
    Apple's i7 options are i7-4770S for the 21.5" and i7-4771 for the 27".

    K-processors aren't used.
     
  16. CompanionCube thread starter macrumors regular

    CompanionCube

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    Aug 3, 2009
    #16
    In this socket type the 4771 is the top i7 option. It works beautifully and the system is insanely fast!!! The best iMac I've ever owned!! :D
     
  17. yjchua95 macrumors 604

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    #17
    If the graphics card isn't soldered, try getting your hands on a GTX780M, EFI-flashed :)
     
  18. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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  19. paukivbashne macrumors member

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    #19
    you can only resolder that one or custom order 27
     
  20. gdourado macrumors 6502

    gdourado

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    Apr 22, 2010
    #20
    Hello,
    I see the i7 27 inch stock comes with a 4471 CPU.
    In the stores I can only seem to find either the 4470 or the 4470k.
    What is the difference between the 4470 and the 4471 and would a 4470 work on an iMac?

    Cheers!
     
  21. Bear macrumors G3

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    #21
    You mean 4771 and there are reports that there are issues if you use a CPU that Apple doesn't use. If you really want to open up your brand new machine and probably void the warranty, get a 4771.
     
  22. mmomega macrumors demi-god

    mmomega

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    Dec 30, 2009
    Location:
    DFW, TX
    #22
    The 6-core i7's are socket type LGA 2011 while the iMac and 4-core i7 are LGA 1150.
     
  23. paukivbashne macrumors member

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    Ukraine
    #23
    guys
    the question still remains
    after countless successful upgrades to i7 4771 never though i will run into such an issue.Resellers stopped selling them due to very very low demand
    so what i have is 4770 and 4770k
    never tried those since 4771 worked flawlessly
    can anyone confirm if 4770k can be used?
    thanks
     
  24. drambuie macrumors 6502a

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    Feb 16, 2010
    #24
    Don't use the 4770k. It is a feature reduced (crippled) designed for raw speed via overclocking, mainly used for PC gaming. There are four functions missing in the "k", including hardware virtualization, (used by Parallels), and trusted execution. The other missing functions are VT-D and TSX-NI. The TSX-NI speeds up execution of multi-threaded software, while VT-D allows a guest OS running in virtualization to directly access peripherals, i.e., Windows via Parallels.
     
  25. paukivbashne macrumors member

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    Ukraine
    #25
    the problem as i stated is that i have no choice!
    if i could i would have used 4771 as before
    i really need to know if anyone tried putting i7 4770k and if it worked without issue
     

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