Upgrade iMac Intel Core i3 CPU to Core i7

Member-Contributed Guide

Member-Contributed Guide

An awesome member of our community made this guide. It is not managed by iFixit staff.

Upgraded my mid 2010 27 inch Apple iMac from a Core i3 3.2GHz (Dual core) upgraded to Core i7 2.93GHz (Quad core) processor.

  • Author: EnglandGreen
  • Time required: 30 minutes to 1 hour
  • Difficulty: Moderate

Upgrade mid 2010 27 inch Apple iMac from a Core i3 3.2GHz (Dual core) to Core i7 2.93GHz (Quad core) processor.

I used this guide for disassembly and reassembly.


Also added a 3TB SATA drive and 32Gb of RAM to max out this system under Lion 10.7

  • Update : Removed the 3Tb SATA drive and replaced with 512Gb SSD and upgraded to Mountain Lion 10.8
  • If you upgrade or change the HD, you will need to buy HDDFanControl software to control the HDD fan which will run at full speed otherwise.
  • April 2013 - 1 year later : This system has been absolutely ROCK SOLID with no crashes, no kernel panics and no freezes!
  • April 2014 - 2 years later : now running OS X 10.9 Mavericks successfully with zero issues. System continues to be fast - but is starting to show its age compared to Sandy Bridge, Ivy Bridge and Haswell architectures! Newer apps are starting to creak at the seams & the beachball is now a fixture.
  • April 2015 - 3 years later. Yosemite 10.10.3. Continuity works but Handoff does not (lacks built-in Bluetooth LE v4.0). Not as fast as my Haswell Macbook Pro or 2010 Xeon 12 proc Mac Pro, but still rock solid. With these simple mods, I have gained years of additional service out of this "obsolete" machine!
  • July 2015 - Running El Capitan 10.11 Beta 5. Only Handoff does not work (see above) but everything else is rock solid. New Notepad app rocks as does a stable version of Apple Mail (at last), and now that the abomination that was 'discoveryd' is dead and the tried and true 'mDNS-Responder' is back, networking is stellar once again.

Edit Step 1 CPU  ¶ 

Image #1

Edit Step 1 CPU  ¶ 

  • Start by gathering your parts, tools, anti-static strap and gloves (gloves are for glass & LCD)

  • Remove glass

  • Then remove LCD. iFixit has step-by-step- write-ups on how to do this.

Edit Step 2  ¶ 

Image #1

Edit Step 2  ¶ 

  • Core i7 2.93GHz Quad Core processor, Arctic Silver thermal compound and iFixit + OWC tools

  • Processor is Intel Core i7 870 2.93GHz 8MB LGA 1156 Quad Core Processor 95W. I bought this CPU used on eBay.

  • http://ark.intel.com/products/41315/Inte...

Edit Step 3  ¶ 

Image #1

Edit Step 3  ¶ 

  • Remove HD, Superdrive and motherboard. Follow the excellent iFixit guides to remove these items.

  • To remove motherboard (a little tricky), I followed this excellent guide - http://www.btobey.com/learn/imac-ssd-ins...

  • Not mentioned in the guide is that you have to remove the IR sitting in back of the front Apple logo before you can remove the motherboard.

Edit Step 4  ¶ 

Image #1

Edit Step 4  ¶ 

  • Flip over motherboard, gently remove 4 x Torx 8 heatsink screws on the bottom (not the big Phillips screws on the top).

  • Please note : Warranty is void with this step.

Edit Step 5  ¶ 

Image #1

Edit Step 5  ¶ 

  • Use Arctic Silver thermal compound remover and preparation solutions to get rid of factory compound.

Edit Step 6  ¶ 

Image #1

Edit Step 6  ¶ 

  • Goodbye Core i3 and hello Core i7.

  • Note arrow on CPU (bottom left in picture). New CPU must be installed in the same orientation.

  • Apply Arctic Silver thermal compound with finger covered in plastic. Spread evenly on CPU only. Guide is here - Applying Thermal Paste

  • Reverse to reassemble. Enjoy the new speed demon!

To reassemble your device, follow these instructions in reverse order.

For more information, check out the iMac Intel 27" EMC 2390 device page.

Required Tools

Heavy-Duty Suction Cups (Pair)

$14.95 · 50+ In stock

Arctic Silver Thermal Paste

$8.95 · 50+ In stock

Pro Tech Toolkit

$64.95 · 50+ In stock

Arctic Silver ArctiClean

$7.95 · 50+ In stock

Comments Comments are onturn off

Ok a word of caution about doing this. I installed an i7 in my 2010 27" i3 iMac and the system works, it reports the correct stats for the i7 but the cpu fan runs at high speed from boot. Annoying! I've researched a number of forums and found no way to resolve this, I also know there are a number of people with the same problem. So either I screwed up my logic board or it just doesn't like the i7 processor. It's the correct processor that people have used the i7 870. I'm at a loss and don't want to pull it out because it just runs so much faster for video editing but using the machine as an audio workstation is now impossible because of the noise from the fan. Also be extremely careful with the LCD screen. just having your shirt brush against it leaves marks and you can't clean it. If you think gloves will solve this you are wrong. DO NOT touch the lcd and be extremely careful with the connectors. If anyone has any ideas about the fan speed fix please let me know!

Carl Geers, · Reply

Also, I assume that you are using this processor?

Intel Core i7 870 2.93GHz 8MB LGA 1156 Quad Core Processor 95W



If you upgrade or change the Apple HD, you will need to buy HDDFanControl software to control the HDD fan which will run at full speed otherwise. I also use smcFanControl to monitor and control the other fans in the system.

As with any modification, your mileage may vary. This is a "Medium" difficulty mod and not recommended for novices to the hobby. I experienced none of the issues your have experienced.

I upgraded to Mountain Lion 10.8 when it was released to the Dev community with zero issues - currently at 10.8.2; I use this machine 'in anger' every day.

I did these mods 5 months ago, and this system has been absolutely ROCK SOLID with no crashes, no kernel panics and no freezes!


If you do the CPU replacement and afterwards the optical drive fan and cpu fan are running at max speed (very loud) then you more than likely didn't plug in the CPU temp sensor. The guide here doesn't talk about it so you can easily forget it! The connector is on the other side of the board, which is different from all the other temperature connectors and not on the same side as the heatsink screws either.

I did this and the computer ran with noisy fans. I used a fan control app to quiet it down, but it was still loud on startup until login. More importantly, the performance without the CPU temp sensor connected was terrible. It was slower than the original i5 CPU. HD videos would stutter and benchmarks gave very low scores.

Make sure you plug in the CPU temperature sensor after you put the heatsink on.


You can solve fan issue just by installing any of the fan controlling programs. I, personally, use iStat Menus. :D

Filip, · Reply

What model was the 3TB HDD?

Art, · Reply

Western Digital "Green" drive - model # WD30EZRX-00MMMB0

My advice : avoid like the plague!

It started corrupting data within 3 weeks. Format, reload OS X, restore from Time Machine x 3. Eventually sent it back under warranty, got a new one, put it in my Drobo.

Put a 512Gb SSD from OWC in the iMac and it's been rock solid ever since.

p.s. Also had a Western Digital 2TB "Green" drive die within 2 months in my Drobo - model # WD20EARS-00MVWB0. I do not buy WD anymore.


The btobey link that you gave is for the 2011 model. Is the layout of the components exactly the same in the different models?

bthompson87, · Reply

Yes, the 2010 model is identical internally.


I have a 2010 iMac 27" and did a CPU upgrade from an i5 to an i7-860 as well as installed an SSD using iFixIt's Dual drive kit and guide. They rate the dual drive install as difficult and 45 minutes. The CPU mod requires more R&R yet is rated moderate and up to 1 hour. First time into an iMac (but with decades in hardware/software support) and the total project took 3.5 hours. I'd keep this at 1 hour and bump the SSD install to 1 hour with a caveat that it could take longer for first timers. I'd also bump this up to "difficult" to match the easier SSD install guide rating.

My temps are running fine on the system post-mod but the fans do run quickly (but not loudly since the loudest thing in the room is the NAS up on the shelf across the room).

onethumb, · Reply

re: WD Green drives are meant as desktop drives and do into error correction mode at times when a NAS is expecting a result. When the Green (or Black) time out for these NAS requests (because they're busy) the Drobo will flag it as failed. I had it happen too. To resolve that, WD has released their RED line of drives that are meant for use in NAS systems and don't "go away for their own housekeeping" like the Green/Black/Blues do.

onethumb, · Reply

Re: WD Green drives. Yes, as I discovered after buying a bunch of them. Replaced with Seagate drives in my Drobos and no issues since. This was my first time opening a iMac and it took me about 55 minutes to complete the upgrade. It would have been faster but I stopped to take photos for this guide. With respect, I do not think this modification rates as "Difficult" so I am leaving it as "Moderate". Use 'smcFanControl' (free) to manage your fans speed (exception is HDD fan).


Hi there!!Very good!I'm thinking seriously to make that at my mac but i don't know what did you do with the power supply for i7????

The best i3 wants the most 65w continuous at heavy load

but the worst i7 needs at least 60w and not under heavy conditions..( have it open for hours rendering...

I'm interesting to know what did you do about this extra wattage..

and as you know if you are so good...consumption create heat...

what did you do with the extra heat? did you upgrade the cooling??

Not to offending you ok? :)

Just wanted to grab whole project from all sides.

Not just working for performance and no reliability :)

Hell7, · Reply

This Core i7 max thermal envelope is 95watts. My iMac has been running 24 hours a day for more than a YEAR with zero issues. I use a combination of HDDFanControl (to turn off the HDD fan) and the freeware smcFanControl to control the other fans. My i7 2.93GHz idles at 35 degrees C @ 999rpm. It never rises above 55 degrees C even under very heavy load (video encoding etc.). Compared to my 2011 Mac Mini with Core i5 2.3GHz which idles at 60 degrees and rises to 90 degrees C under load. See my Core i7 Fan settings and Temperature pics here - http://grond.tv/i7temp/i7temp1.jpg - http://grond.tv/i7temp/i7temp2.jpg - http://grond.tv/i7temp/i7temp3.jpg


Nice my friend!! I'm thinking to do it too.i saw that you did it very well :)

and after these infos you reply to me i saw that is ok.

My respects :)

Hell7, · Reply

Just did it. Nice ..and big difference :) Watch out there for not GENUINE INTEL Processors.

Recommended only to experience persons and well known what they are doing in my opinion

Very good guide.

Hell7, · Reply

Finding mixed info regarding compatibility of Core i7 875K with iMac (Late 2009/2374 27").

Does anyone KNOW if the unlocked i7 875K will work in the Late 2009?

I've found info where Apple offered the same processor as an iMac 2010 option.

Thanks and great guide btw.

Mitchell, · Reply

According to MacTracker, the 27" iMac (Late 2009) offered a Core i7 (860) ("Wolfdale, Lynnfield") on the 2374 using the LGA1156 socket. Intel details here - http://ark.intel.com/products/41316

The i7 (860) uses the same socket as the 875, so it should work. The TDP is the same (95W) but the multiplier is 22x instead of 21x. I do not think that will cause any issues.

I have 2309, which is a Core 2 Duo 27" iMac (Late 2009) as well as the 2010 model in this Guide, and that processor cannot be upgraded to anything useful.

Thanks for the kudos and please post if your upgrade is successful.



I had a less than successful attempt at this :(

I have a mid 2010 21.5" iMac with i3 CPU. I bought an i7 870 off ebay - used, but from a reliable seller so assuming CPU isn't at fault.

Installed the i7 as per the guides and it failed to boot.

After changing my underwear :-P I refitted the old i3 and bingo, booted back up as normal.

Anyone know why this would work on a 27" iMac and not a 21.5" one?

(I'm going to take the CPU to a PC repair shop and see if they can test it, just to be sure)



David Rowe, · Reply

Hi David,

Unfortunately I do not have a 21" iMac to try and replicate the problem; I do not know if the motherboards are even the same as the 27" iMac. Sorry. Good luck finding a fix and let us know what the outcome was.



A million thanks! I am in the market for my first desktop and am juggling the options of buying a prebuilt computer, or building my own. I never thought the iMac could be upgraded until I came across your article. I've learned the RAM, CPU, and hard drive can be replaced. I like the idea of using an SSD over a HDD.


The level of expand-ability is key to what I'm looking for. Even though these things can still be expanded, they still cost nearly twice as much as one built from the ground up... But I guess the monitor might be worth it.


I would call myself a novice, but I have taken apart an Xbox and other devices completely apart, switched out parts, and put them back together without breaking them.

Remrie, · Reply

Glad my writeup was helpful! Apple gets a bad rap for upgradeability, primarily because people compare Apple to generic tower-style PCs. In fact, it would be better to compare Apple computers to other major branded PCs - like HP, Dell, Lenova (formally IBM) etc.

Upgrading a HP desktop processor, power supply, on board GPU etc. is nigh impossible. The same holds true for most major PC players (Dell/Lenova etc.). This is by design.

Apple is extremely upgradeable - for a major brand - but can never be compared to a home-brew PC which will always be far more flexible, expandable and upgradeable.


Price wise, you get what you pay for. The beautiful 27 inch IPS 2560x1440 monitor of the iMac would be around $900-$1000 by itself, but it is never taken into consideration when pricing so-called "like for like" Macs versus PC prices. Everyone looks at the latest ASUS i7 Ivy Bridge or Haswell CPU-based motherboard, a $100 case and a $80 power supply and say "Apple is too expensive and is ripping the fanboys off".

But if you look at ALL of the components plus the packaging, you will find that Apple is very competitive on pricing against major brand (like Dell, HP, Lenova etc.)

The iMac is a marvel of engineering, packaging, fit and finish and is upgradeable via CPU, GPU, RAM, hard drive and optical storage. The trick is not to treat Apple any different from any other major PC vendor.

The 2010 27 inch Core i3 iMac is a great bargain at well under $1000 and can be upgraded to the performance of an Ivy Bridge-based iMac with a little patience and money. Good luck!


OK. I have an update on my 21.5" i3 upgrade. After reading around, I came to the conclusion that the 21.5" motherboard just won't supply the juice to run an i7 CPU. I resold my 2nd hand i7 CPU and bought an i5 680 CPU instead. I fitted the i5 and it worked fine. I'm just not sure if the i3 to i5 upgrade is actually worth the hassle, but at least it has satisfied my curiosity. :)

David Rowe, · Reply

Thanks for the update! This will help someone trying to make that modification to their 21" iMac!


Thanks, I just did the same thing ... now I know why the i7 is not starting up ...


Not enough juice. This is exactly why. The motherboards in the 21.5" only are capable of 73w TDP. Found this answer in another iFixit thread: https://www.ifixit.com/Answers/View/8728...

Then I checked for myself:


Only came with 3 processors, each were only 73w TDP.



*should* (don't quote me on this) be a list of compatible processors for the 21.5" model

I care so much because I almost made the same mistake. Had a i5-760 laying around from and old upgrade elsewhere. I sure am glad I always researched first before I starting disassembling.


I just did the I7 cpu upgraded with my 27 inch imac as instructed. However, upon startup, the fan noise is so loud. I installed the Fancontrol software as some suggested without any resolutions. Is there something else I can do?


lancele, · Reply

Did you change your hard drive as well? If you did, you have to buy HDDFanControl. If the fan noise is from the CPU fans, it should not do that. But you can control the rest of the fans with smcFanControl (free).


no, i did not change the hard drive. yes, the fan is from the cpu . It said it is at 3825 rpm. maybe i did not put some wire back correctly.

lancele, · Reply

That would be my guess.


I want to do the i7 870 upgrade on my 201 27" iMac but I want to know what exact processor info I need when buying one from eBay. Also since I am not going to upgrade the Apple HDD I shouldn't run into any fan issues or power requirements correct?

John, · Reply

The processor is described in detail in the build (above) - Intel Core i7 870 2.93GHz 8MB LGA 1156 Quad Core Processor 95W.


Theoretically you should not have any fan issues - the majority of upgraders had no issues - but a few others (posted here and on forums) did have fan problems so be advised.


I did the upgrade, and have two significant issues.

1. The ODD fan is running constantly at 3500 rpm and is really loud.

2. The system info still reads the processor as an i3 and my geek bench score actually decreased by almost 1000 points.

Anyone had any issues with these things?

Joel Olson, · Reply

1. This might help - https://discussions.apple.com/message/18...

2. That is very odd. First time I have heard of that problem


Update: I reset the processor and now my score is back up where it should be around 7800. The processor still shows up as an i3 on my system but geek bench reads it as an i7.

As for the fan It now says its running at a reasonable 996 RPMs but the fans are all still really loud. any ideas? Can i start the computer up without the screen to see exactly which fan it is that is making all the noise?

Joel Olson,

In theory, you should be able to connect an external monitor to the Display Port and start the iMac with the screen removed, however I have not tried this so I cannot confirm if it will work or not.


Hi, great guide! Having read through all the comments - I am worried that I might have fan issues. 27" mid 2010 2.8 GHz Core i5 (I5-760) iMac which I want to upgrade to 2.93 GHz Core i7 (I7-870).

Do you think I will have Fan issues? Also will it make a big difference in speed?


Pritpal, · Reply

Thank you!

Regarding the fan issue - it appears to be in the minority based on my limited research; I certainly never experienced any fan issues beyond the self-inflicted ones I created by changing the Apple hard drive (easily fixed by purchasing HDDFanControl).

As to if there is a big difference in speed - a resounding "YES!" After I upgraded to the 2.93GHz i7, my aging iMac felt like a new machine. The SSD I installed later also played a major part in that impression, but even with the 3Tb hard drive I installed with the processor upgrade, the speed increase was palatable. iPhoto, Aperture, Final Cut Pro, Merlin - everything ran faster, responded faster, rendered faster.

The upgrade added another 3 years of useful service to my primary work machine. Now running Mavericks 10.9, my iMac feels and responds the same as my other, much newer Macs ('11 Mini, '11 & '13 MBAs, '11 MBP).

I'm saving my pennies for the new '13 Mac Pro (black trashcan) but until then, this is the fastest Mac I own (even faster than my '08 dual proc Mac Pro)


I see that you added 32 GB of RAM to this system. According to all of the info I have found, the max is 16 GB (including the i7 processors). Can I add 32 GB to the mid-2010, 27" i3, or would I have to drop in the i7 to access 32 GB?

Richard Johnson, · Reply

I'm not sure what your source of information is.

MacTracker has this to say -

* Maximum Memory 32 GB (Core i5 or Core i7 Actual) 16 GB (Apple)

* Memory Slots 4 - 204-pin PC3-10600 (1333 MHz) DDR3 SO-DIMM

I have had no issues running 32Gb of RAM on this iMac with the i7.


I upgraded to the i7 as well. Turning it on, I also had an issue with both the CPU and the Optical drive fans running at ~3800 RPM constantly. Pulled the display again and found the LCD temp connector unplugged. Reattached and all is well now. Hope that helps.

William Sisk, · Reply

I want to do this to my mid 2011 i5 27inch iMac. Will all the part be the same as the guide? or will it be different?

Bone, · Reply

William, good to know. Thanks!

Bone, I do not know as I do not have a 2011 iMac to experiment on. Sorry.


I just did this today. Took us about 2 hours. Very excited. I got it home and put into under a load test by rendering a video in Compressor. This things is blazing hot! Temperature Gauge Pro app has the CPU running at about 88-90. Fan just about at 2000 RPM. (I can't even leave my hand on the top border of the case.) Is this okay? Or do we need to go back in and take a look at the heat sink and thermal compound?

Ben, · Reply

Yes, I would suggest that you may have missed some thermal compound or securing the heatsink or something of that nature. My temps are 31 degrees C and my fans run at 1300rpm (fan speed set with smcFanControl) and they have been consistent since I did the upgrade early last year.


I talked to a friend and based on what I described, he thinks I put too much thermal compound. Going to go back in tomorrow and redo it. At idle, it runs about 22 C; and like I said, under a full render load, it ran 90 C.


I redid the thermal compound. There was definitely too much. It was squeezed out all the sides. But... when we got it back under a full processing load, the temp was back at 90-92 C in about 20 min. So I downloaded the smcFanControl app and pushed the fan to 1800 rpm. That brought the CPU temp down to 80 C where it held for the rest of the render (~2 hours). Is that safe?


Still too high, in my opinion. I'm not sure what the problem is.


Well, I'm not so sure any more. For every person that says too high, there is someone who says it is fine. I have a macbook pro at work and ran a render in Compressor on it just to compare temps. It was in the mid-80s within a few minutes. So I think it's going to be okay.



To upgrade iMac 27" mid-2010, can you use Intel Xeon X3460 2,80 GHz, because it uses same LGA1156?

jjussicom, · Reply

The TDP is the same (95W) but I do not believe that the iMac motherboard/firmware will support a Xeon processor even though they use the same socket. It was never designed for the Xeon series and the Core series is different. However, if you try it and it works, let us know please!


Not sure if anyone can help. I have just upgraded from an i5 to i7 and everything seems the same as ever temperature-wise and fan speed is fine. However I am getting random lock-ups / freezes. Everything just becomes unresponsive - mouse, keyboard etc. If in sleep mode, it won;t come out of it (but does lock up when not asleep). Bizarrely I have a 2nd monitor and a desktop clock app on that, and the time still keeps going on that whilst the iMac is apparently frozen! I have checked that all wires are where they should be, and just can't work this out. There is nothing in the logs to point to anything and there isn't a crash log created.

Steve Foxon, · Reply

Sounds like possibly thermal paste not applied correctly or a bent pin/connector somewhere making intermittent contact. My system, now 2 years since the upgrade (April 2014) has been rock solid. No lockups, no kernel panics, no freezes. I suggest you double/triple check your system. Another possibility is you might have a bad processor. Hope this helps.



is this possible in the late 2009 IMac? Is it the same layout?

Ira, · Reply

No, the 2009 iMac is a Core 2 (Conroe) architecture. This particular upgrade will only work on the Core i3/i5/i7 (Nehalem) architecture.



have installed a I7 870. The whole was exactly 20min. After that the system is shut down and has only beeped .... I3 used again and everything is ok again. Was the I7 defective or has someone something also soo ever had ...

Chrissi, · Reply

error Massage

Anonymous UUID: 9D3D914F-7803-DB30-2691-7BA57DBD576B

Wed May 28 20:18:22 2014

Machine-check capabilities: 0x0000000000001c09

family: 6 model: 30 stepping: 5 microcode: 5

signature: 0x106e5

Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz

9 error-reporting banks

Processor 0: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Processor 1: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Processor 2: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Chrissi, · Reply

Processor 3: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Processor 4: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Processor 5: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Processor 6: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

Chrissi, · Reply

Processor 7: IA32_MCG_STATUS: 0x0000000000000004

IA32_MC6_STATUS(0x419): 0xfe2000400030014a

IA32_MC6_ADDR(0x41a): 0x00000000035a1e00

IA32_MC6_MISC(0x41b): 0x0000000000041014

IA32_MC8_STATUS(0x421): 0xb20000000004008f

panic(cpu 1 caller 0xffffff8006cdc7e9): "Machine Check at 0xffffff7f884993f2, registers:\n" "CR0: 0x000000008001003b, CR2: 0x000000010cfcc050, CR3: 0x0000000009903000, CR4: 0x0000000000000660\n" "RAX: 0x0000000000000020, RBX: 0xffffff8019710000, RCX: 0x0000000000000001, RDX: 0x0000000000000000\n" "RSP: 0xffffff8109b63d50, RBP: 0xffffff8109b63d80, RSI: 0x0000000000000006, RDI: 0xffffff80195eec00\n" "R8: 0x0000000000000000, R9: 0x0000000000000006, R10: 0xffffff8109b63c50, R11: 0x0000000000000200\n" "R12: 0xffffff801955cdc0, R13: 0x0000000000000006, R14: 0xffffff7f884b5e20, R15: 0x00000000000007b0\n" "RFL: 0x0000000000000046, RIP: 0xffffff7f884993f2, CS: 0x0000000000000008, SS: 0x0000000000000010\n" "Error code:

Chrissi, · Reply


Backtrace (CPU 1), Frame : Return Address

0xffffff8109b05e80 : 0xffffff8006c22fa9

0xffffff8109b05f00 : 0xffffff8006cdc7e9

0xffffff8109b06060 : 0xffffff8006cf3cff

0xffffff8109b63d80 : 0xffffff7f88491676

0xffffff8109b63e70 : 0xffffff7f884908d9

0xffffff8109b63f30 : 0xffffff8006cdd81c

0xffffff8109b63f50 : 0xffffff8006c375ba

0xffffff8109b63f90 : 0xffffff8006c37908

0xffffff8109b63fb0 : 0xffffff8006cd7127

Kernel Extensions in backtrace:


BSD process name corresponding to current thread: kernel_task

Chrissi, · Reply

what do you think? If the CPU is defective? Kern1?

Thank you

Chrissi, · Reply

My guess is yes - bad i7. Kernel panics with the only change the CPU suggests as much.


I have a friend that owns an electronic sales repair company, and he called me because he had no luck finding the same problem, he assured me that he had already checked and repasted the CPU w/thermal compound, long story short after a couple hours at looking at other things and giving up I sugguested we take the CPU/Cooler assembly back down for inspection and with the help of a magnifying glass found three of the round shaped gold plated contacts on the bottom surface of the chip, where it makes contact with the motherboard to be burned and there was no way these (Balls) were making any contact, this was an unopened gateway system, never worked on, and no they werent knocked off by abuse, would have to be a thermal issue , also the opposite corner of the processor actually had a darker color in a small spot from excessive heat, you would have to see the pictures we took to appreciate the find that was so hard to see, but just an idea for you to check...will see if i can post the photos..good luck


Just upgraded my ''27 2010 iMac from i3 to i7-870. No issues with fans. All tests and programs see the i7 and use all its cores but - "About this Mac" still showing i3)) Any ideas how to reset/update system profiler? Thanx.

digimatix, · Reply

Possibly a SMC reset? Or PRAM reset? I did not have this problem so I do not know.


Hello, fantastic guide. Question, I noticed you upgraded to an SSD years back. I'm about to embark on the same journey, but am having trouble finding a guide for the mid 2010 (MC510LL/A) 27" model. I plan to upgrade CPU, HDD, and RAM in one shot. I'll use this guide for CPU, but What SSD and accessories did you need?

Jack Young, · Reply

Mid-2010 27" iMac is identical to this guide. RAM is by Komputerbay, bought on Amazon.

SSD is a Mercury by OWC. I use OWC for most of my upgrade needs - http://eshop.macsales.com/shop/SSD/OWC/


Good morning my friends,

so now a new attempt. I7 bought with operational guarantee, installed and lo and behold .... everything works as it should. Temperature values ​​i.o.

Thank you for this great tutorial. Did this time only 30min brewed.

Then installed is 32GB of memory. Runs are now 10 days perfectly.

Chrissi, · Reply

Excellent! Thank you for sharing!


I tried to upgrade my iMac 27" 2010 mid with a SSD and 4TB HD.

However, when i reassembled the iMac, it won't turn on, instead it keeps beeping around the 5 seconds. After some googling I am afraid that I screwed up the CPU somehow. Or maybe even worse, the logic board itself, but because the CPU is so tucked in tightly I can't even imagine to screw that up.

So I'm facing a real problem with a real dilemma how to fix this. Either the logic board is broke or my CPU is faulty. I need to figure out what's wrong first. I don't have any other motherboards with a socket 1156.

So what is the best bet to figure out what is broken? My first thought is to get an i3-550 core. It's cheap 35 euro's. If it does work, i'll buy a new i7 core.

Or are there some other ways to find out what's is wrong? I'm a missing something? Thanks in advance.

Forrest Gump, · Reply

I successfully replace my i3 processor with the i7 following this guide (along with this one https://it.ifixit.com/Guide/Installing+i...).

I was with a friend of mine and we both have advanced skills on computer teardown.

It took approximately 3 hours and 15 minutes to:

1) remove the ODD;

2) add a SSD (to have the fusion drive);

3) replace the i3 with the i7;

Nothing went wrong and the reassembly was fine at the first shot.

I suggest to carefully remember (maybe taking some notes) where the connectors were because some of them can be easily confused.

I don't have any fan problem so far and I'm not using any software to speed them down.

Moreover, I re-connected the ODD thermal sensor nearby the SSD to prevent any possible error or clash on measured temperature by the OS.

This tweak leads to an incredible boost to the iMac. I strongly suggest to do it!

Claudio Fantacci, · Reply

Awesome! Thanks for the write up!


So can i do it in an iMac mid2010 i3 3.06 Ghz?

I want to replace the i3 with the i5 680...

will i have problems with heat for example?Or simply i can do it?

appleuserfan, · Reply

I don't think it'll work. I believe the i3 has a different voltage/power requirement if I remember correctly and will not supply enough power to a i7 CPU.


Yes, you can go from the i3 to the i5 as long as it has the same socket type.


Yes i know intact i just want to put an i5, not an i7. Can i do it?

appleuserfan, · Reply

hi do you know if i would be able to up my early 2008 model, 2.66 GHz Intel Core 2 Duo it so slow.


philip pomerance, · Reply

No, sorry, you are stuck with what you have as far as I know.


I did this mod with 2.93 i7, 32GB RAM upgrade and a 4TB Hybrid drive. Its as fast as anything I need and cannot see spending money for a new iMac. No issues, rock solid on Yosemite 10.10.3

tessiergreg, · Reply

Excellent! I'm running El Capitan 10.11 Beta 3. Only Handoff does not work (no LE Bluetooth) but everything else is rock solid. New Notepad app rocks as does a stable version of Apple Mail (at last), and now that the abomination that was 'discoveryd' is dead and the tried and true 'mDNS-Responder' is back, networking is stellar once again.


Absolutely fantastic.

I picked up a Core i3 27" iMac at a rock bottom price of only $475 and started wondering about upgrading the internals and I run across this!

It appears that the iMac I own has a MXM slot, so I might get a little dirty and order the 6970M from the 2011 high end iMac and see if fitting it in here will work out. I am a little worried about the TDP, but I will do my research and see the increase power consumption. I would assume that it won't be too much more.

Either way, great guide and will be attempting this late next week. Should be a fairly simple upgrade as I've worked on older generations of iMacs in the past!


Julius Kodes, · Reply

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