iMac Graphics Problems

Posted:
in Genius Bar edited February 2015

I'm having various issues with my Late 2012 27in iMac running Yosemite with 3.4 GHZ Intel Core i7, 32 gig of ram, and NVIDIA GeForce GTX 680MX 2048 MB. 



While using premiere, after effects, photoshop, or doing any sort of graphics heavy program I experience blue/purple lines and distorted screen or images. It happens while playing video, or not. It also exhibits strangely and sporadicly. At times my system has been known to crash and restart. 



I just saw that the Macbook were getting a repair - but this looks like the same issue. 



Any thoughts? What can I do? 



 

 

 

 

 

 

 

Comments

  • Reply 1 of 4
    MarvinMarvin Posts: 15,310moderator
    I just saw that the Macbook were getting a repair - but this looks like the same issue. 

    Any thoughts? What can I do?

    It looks like a GPU corruption. Apple setup a program for the 2011 27" models with the AMD 6970M:

    http://support.apple.com/en-gb/HT203787

    but I don't think there is one for the 2012 ones with the NVidia GPUs. Try booting up in safe mode by holding shift to clear out your driver caches, that will disable the GPU in that mode. If you still get the corruption after rebooting back into normal mode, you'll need to take it in for repair. They'll probably charge for the repair.

    Sometimes these failures will happen without there being a widespread defect so Apple won't offer free replacement.
  • Reply 2 of 4
    Originally Posted by Marvin View Post

    AMD 6970M:



    NVidia GPUs.

     

    Why do we find this acceptable? Not from Apple, from the industry. These are the only two companies that make GPUs and they both fail left and right. It’s completely unpredictable.

  • Reply 3 of 4
    MarvinMarvin Posts: 15,310moderator
    Why do we find this acceptable? Not from Apple, from the industry. These are the only two companies that make GPUs and they both fail left and right. It’s completely unpredictable.

    Intel makes GPUs too (they have over 65% of the market now) but the high-end is pretty much AMD/NVidia. The failures are unpredictable but we don't know what the failure rates are overall. NVidia's financial report for 2014 says:

    "We recorded a net warranty charge of $193.9 million and $94.0 million during fiscal years 2011 and 2010, respectively, towards the repair and replacement of products arising from a weak die/packaging material set used in certain versions of our previous generation MCP and GPU products."

    They made about $3.5b in revenue during those years. If we assume an average price of $50 per chip based on overall revenue and unit volume, that amount would be around 2-4 million failed units (about 5% failure rate when there's a defect, likely less as it would be higher-end and more expensive units).

    AMD's filings suggest 1.5% failure rate from warranty charges.

    They each ship over 60m units to consumers so even 1% failure rate will result in 600,000 units exhibiting problems and online we only read about a handful of stories.

    If there was a more expensive way to develop more reliable chips (say $1-5 per GPU), it would still be cheaper for them to take a hit on warranties than make them more reliable. Profitability is further improved when you consider that out of warranty failures will result in another purchase.

    Intel CPUs/GPUs don't seem to suffer from the defects nearly so much. It's not going result in a positive outcome for NVidia/AMD's reputation. Computer manufacturers like Apple are moving away from dedicated GPUs anyway. Apple only has a single laptop model with a dedicated GPU and it starts at $2500 and in the iMac, the dedicated GPUs start at $1500.

    With Skylake this year, which should be around the performance of an NVidia 850M, I could see Apple ditching dedicated GPUs in the last remaining laptop model and all but the two top iMacs and Mac Pro. This would reduce dedicated GPU models to under 5% of their lineup or at most about 1m units per year, which reduces the potential failures.
  • Reply 4 of 4
    hmmhmm Posts: 3,405member
    Quote:

    Originally Posted by Marvin View Post





    Intel CPUs/GPUs don't seem to suffer from the defects nearly so much. It's not going result in a positive outcome for NVidia/AMD's reputation. Computer manufacturers like Apple are moving away from dedicated GPUs anyway. Apple only has a single laptop model with a dedicated GPU and it starts at $2500 and in the iMac, the dedicated GPUs start at $1500.



    With Skylake this year, which should be around the performance of an NVidia 850M, I could see Apple ditching dedicated GPUs in the last remaining laptop model and all but the two top iMacs and Mac Pro. This would reduce dedicated GPU models to under 5% of their lineup or at most about 1m units per year, which reduces the potential failures.

     

    The problem in recent ones is presumably bad soldering between the GPU and board, which may not even be under AMD's or NVidia's control. I'm skeptical that we'll actually see skylake this year, but this repair program runs for a while. If I have another notebook death after that, I won't touch a Mac (notebook) with discrete graphics. Intel graphics don't have to be perfect. They just have to be close enough to mid range notebook GPUs. Even gaming notebooks rarely go past that range in 15" notebooks.

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