In a somewhat baffling piece of news this weekend, word comes that Apple has initiated an internal replacement program for the video cards on some of their mid-2011 27” iMacs. Specifically, Apple is running into issues with the AMD’s Radeon HD 6970M that’s used on the upgraded Mid-2011 27” iMac. In a notice being circulated to Apple support staff, Apple provides a brief description of the issue:

Apple has determined that some AMD Radeon HD 6970M video cards used in 27-inch iMac computers with 3.1GHz quad-core Intel Core i5 or 3.4GHz quad-core Intel Core i7 processors may fail, causing the computer’s display to appear distorted, white or blue with vertical lines, or to turn black. iMac computers with affected video cards were sold between May 2011 and October 2012.

Jumping right into the heart of the matter, what makes this issue so stupefying from a GPU review’s perspective is that this is the first indication we’ve seen of there being an issue with this AMD GPU. The Radeon HD 6970M is of course one of the mobile variants of the Barts GPU, otherwise known in AMD’s mobile lineup as Blackcomb. Barts in turn is part of AMD’s second generation 40nm silicon, released in late 2010 well after TSMC got the kinks out of their 40nm process. As a mature product released on a mature node, at first glance there doesn’t seem to be any reason for the Barts GPU to be having longevity issues.

Meanwhile as far as implementations go, the 2011 iMacs use MXM cards, which means unlike some other Apple products the video card isn’t being soldered on directly or otherwise being assembled by Apple, greatly limiting Apple’s role in the implementation of the product. MXM allows Apple to simply order and install finished video cards from suppliers, and is also why they are able to fix the affected machines so easily, since the video card is directly replaceable. At the same time however Apple is far from the only OEM using 6970M MXM cards, which means that if the root cause of the issue is a bad video card – no matter the specific component – then any other 6970Ms may also be affected.

2011 iMac With MXM Video Card. Image Courtesy iFixit

Anyhow, we’ll avoid speculating too much here since there’s not nearly enough information available to properly identify the cause of the issue. But given just how rarely we see large scale video card longevity issues, this is somewhat worrying; solid state parts simply don’t fail that often. After all, it took a fairly serious GPU underfill issue to cause NVIDIA’s 65nm GPU failures (Bumpgate). We don’t expect the root cause of this failure to be nearly as drastic given the already-mature status of AMD’s 40nm production process, but it will still be interesting to see what that cause is, assuming we ever find out.

In any case, for affected iMac owners 9to5Mac has the full details of the replacement program, including the models and serial numbers covered. Apple will be covering the cost of the replacement for 3 years, regardless of warranty, though as is the case with most programs of this nature they are only replacing failed video cards.

Source: 9to5Mac

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  • solipsism - Sunday, August 18, 2013 - link

    It could be poor cooling just over the GPU but there are other components in the chassis that seems to have less issues. Whether this is an Apple design flaw or not we can't determine but I do know that powerful GPUs have had longterm use issues long before the iMac was around.
  • nerd1 - Sunday, August 18, 2013 - link

    Cramming powerful hardware into tight package? Come on, 6970m is a god damn LAPTOP GPU!
    We now have 2x more powerful GPUs (675m) in 13 inch laptops like 230ST.
  • RussianSensation - Sunday, August 18, 2013 - link

    AMD & NV GPUs have no problems running at 85-90*C 24/7 for 2 years in a row. I tested plenty just for fun. Never had any failures with either brand. It has to be some component related issues, not temperatures.
  • Kevin G - Saturday, August 17, 2013 - link

    If I had to guess, I'd say it was simply over heating in the iMac chassis. For reasons I cannot fathom, Apple has been chasing the whole concept of thin for their iMac line like they do their laptops. Some one should tell Apple that few extra milimeters of depth for an all-in-one desktop isn't the end of the world. I dread to see how the late 2012 models are going to last long term....
  • solipsism - Sunday, August 18, 2013 - link

    I don't see how adding a "few extra millimeters of depth" would help. I could even see an argument for how it could hurt using Simon42's comment about the chassis acting as a heat sink.

    If it is an issue with heat and that issue can be solved with better cooling then that should be the resolution, not simply making the chassis a little bigger. If the improved cooling requires more room in the chassis then that should happen but that a circumstance of the solution.

    It seems to me Apple would have done plenty of testing on these iMacs to see how hot the internals got under load and yet they've moved from using mobile-class chips to desktop-class chips and continued to make it thinner so I have to wonder if the problem isn't simply not enough attention given to proper cooling.
  • David_K - Sunday, August 18, 2013 - link

    The CPU always were "desktop class" , but the GPU's are still mobile chips and not desktop ones.
  • geok1ng - Sunday, August 18, 2013 - link

    AFAIK, iMacs use laptop cpus, in laptop mobos, with laptop graphics, if any. That over course never stopped apple from charging server-grade prices for them.
  • plewis00 - Sunday, August 18, 2013 - link

    It sounds like you've done stunning little research on what is actually inside an iMac... They use desktop CPUs, on custom-designed mainboards (just like a SFF desktop or laptop) and discrete laptop graphics (in the past low-mid range desktop chips were in use).

    It's a premium computer where most of the cost is probably in the LCD panel and chassis actually - not a lot different to Dell XPS or high-end HP all-in-ones that also cost more money...
  • solipsism - Sunday, August 18, 2013 - link

    I don't get what you mean by a "laptop mobo" since it's a custom design. All I can think of is that only have having a bunch of PCIe slots on the mono means it can't be used for a desktop PC.
  • KoolAidMan1 - Thursday, August 22, 2013 - link

    They use desktop CPUs in their iMacs. My late-2009 model has an i7 860

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