Imac display issues following Yosemite upgrade

I had a major issue with non-Apple RAM when I first got my 2010 iMac. I maxed it out to 16GB with 3rd party RAM and it kept shutting itself down randomly and doing weird performance things. I eventually got it replaced with official Apple RAM (I think it's Samsung) for this machine and that solved the problem. Since I'm having these graphic issues with official Apple RAM, my unofficial guess is that your Corsair RAM isn't contributing to this particular issue.

Yes, I thought the same so I took out the Corsair memory and put 8GB (4 x 2GB) of original Apple memory and it worked fine for about 12 hours but this morning the display artifacts came back again. I did a second partition in my HD where Yosemite is installed so this morning booted up on Mavericks partition again and I'm gonna stay there till a fix comes out. I'm like 95% sure this is a Yosemite driver issue.

Back on Maverick again, Display glitch was too annoying, unfortunately I already updated my Apple account to iCloud drive, that *****. Stay with Maverick until a fix is published. Don't think it's a memory issue either. I replaced the original memory by Kingston 4 x 4 GB pieces with no problem. System runs with no glitches on Maverick again. I'm wondering, that this issues is only affecting a handful of systems.

The peculiar thing is that I was experiencing this in Mavericks, but only to a small degree. It was a few random squares here and there vs. the giant pattern across the screen I'm seeing now. Once my machine warms up, though, the problem dissipates. I think it's affecting a good many iMac users - there's another thread about this that's 20-something pages long: Red and green square dots?

Other communities reporting the same problem:

http://feedback.photoshop.com/photoshop_family/topics/photoshop-cc-on-yosemite-g raphics-problem

iMac (mid-2011) 27" here with the same problem. It was doing it on Mountain Lion but was tolerable. Just went to Yosemite and it's crash after crash. One of the other threads has people taking their video cards out and putting them in the oven to re-set the solder. I don't really want to have to do that! Is that really the answer? If I take this to Apple are they going to charge me for a video card that's just going to have the same issues down the road? Any more suggestions?

Welcome to the fold!

Yes, and yes to your queries: YES, it appears that baking the video card seems to be the solution with the greatest effect and longevity and YES, Apple will charge for ANYTHNING related to your machine due to its age (mine is a mid-2010 27" iMac i5 with the same issues)!

I may reluctantly have to set aside time this weekend, to accomplish this tedious repair, myself.

Elsewhere on these forums, mention is made of a class-action suit filed on behalf of 2011 MacBook Pro owners for these very same issues: Perhaps we should inundate those legal representatives with our identical difficulties, and they could emend/expand their suit to include us, too?

"

The plaintiffs are represented by Gary E. Mason, Steven N. Berk, and Esfand Y. Nafisi of Whitfield Bryson & Mason LLP, and Michael Ram of Ram, Olson, Cereghino & Kopczynski. For more information about the lawsuit, contact Esfand Nafisi by email at enafisi@wbmllp.com or by phone at (202) 640-1167.

The name of the case is Book et al. v. Apple, Inc. No. 5:14-cv-0476 (N.D. Cal., filed Oct. 24, 2014)."

http://9to5mac.com/2014/10/28/apple-class-action-lawsuit-2011-macbook-pro-gpu-gr aphics-issues/

http://9to5mac.com/2014/10/17/2011-macbook-pro-gpu-complaints-not-going-away-as- petition-reaches-18k-signatures/

http://www.cnbc.com/id/102129683
http://www.macrumors.com/2014/10/28/macbook-pro-2011-graphics-lawsuit/

http://appleinsider.com/articles/14/10/28/apple-hit-with-class-action-lawsuit-ov er-2011-macbook-pro-graphics-failures

It is not just limited to iMacs. I am having problems with a 2012 2.7gHz quad core i7 Retina MBP. Getting the same error message in Console just prior to display problems, followed by the cursor locking up and a crash.

29/10/2014 07:45:53.000 kernel[0]: BUG in process suhelperd[371]: over-released legacy external boost assertions (1 total, 1 external, 0 legacy-external).

I am on my third install of Yosemite. The first one scrambled the file vault unlock key so that the MBP would not even start and I had to wipe the hard disc. Second install worked for a while but loads of connectivity problems and finally after doing a PRAM reset, it would only start in safe mode. Third install seemed to be working sort of OK until this morning, when had the above issue, which looks similar to iMac problems.

In spite of the Beta testing by 6 million folk, this seems the buggiest OS release since Panther.

Wilson

I have the same problem. It existed to a very small extent on Mavericks. I just barely noticed it as some occasional flickering square pixel patterns in the upper left corner of the screen. This is a iMac 27" core i5 from 2010.

I thought upgrading to Yosemite might help. Nope.

It got vastly worse, with whole rows of pulsating pixels obscuring menus and sometime modifying my cursor from its usual black arrow to a small square of pixel blocks.

After trying the usual things, as suggested in the many posts above, I concluded it must be a HW problem, since it existed to a small extent under Mavericks.

I lugged the 27" behemoth to the Apple store, where, of course, it worked perfectly. I left it with them for 7 days. After the first 4 days, they told me they saw no problems and all diagnostics ran fine. A few days later, they called and said they saw the bad pixels and the machine failed its cpu heatsink test and I needed a new main board for about $550.

I declined the repair and took the machine back to my office. It's been running perfectly, with a small desk fan blowing air across the back.

Perhaps this really is heat related and Yosemite is causing the GPU to run hotter? Anyway, it's been fine for about 6 hours.

I'll keep you posted if it goes bad again.

Interestingly, the Apple Genius said he had not seen this kind of problem before. Considering all of the discussions on this site, I'm surprised.

I am experiencing the same issues with my 2010 model MC511LL/A - red/green pixel squares were a modest problem on Mavericks over the past 6 months or so, and the upgrade to Yosemite made things significantly worse. Now the computer is virtually unusable due to slow performance & screen rendering issues. The information bar at the top of the screen often contains several layers of overlaid menu items, and the red/green space invaders have taken over the whole background.

This is all very frustrating... I've read every thread on the planet and have yet to hear of a reasonable hardware or software solution, and it appears that Apple is not taking any action. If this was just a slow performance problem, I would understand, this iMac is only 4 years old and it's about to hit the junk pile... makes me consider running away from the Apple ecosystem as quickly as I ran to it in 2010. I also now realize the folly of buying an all-in-one desktop computer.

I turned on "Reduce transparency" in System Preferences > Accessibility > Display and that seems to have fixed the issue for me.

Just tried that, but doesn't seem to help during an active pixel storm. Will see if it helps upon restarting...

Update:

Still did the pixel thing a tiny bit upon restart but so far no major problems as before. This seems to have helped a bit, however as my machine warms up, the problem also dissipates. Hard to tell which it is, but hopefully will continue. Thanks for the tip!

I have found when I open 3 or more finder windows that the problem all but disappears. As soon as I close one of the last of the three opened finder windows the problem reappears. I believe there ATI graphics chip has a race condition problem exasperated by the new driver in Yosemite and when three or more finder windows are opened the refresh is slowed down enough to prevent the problem

JPP, thanks for the transparency tip: I'd experienced my first really aggressive "storm" last Friday - so bad that when pull-downs were accessed, even those were virtually unreadable, due to the "snowstorm" that filled them..

I attributed it to the falling temps in my home office (upper floor library of a 1900 restored Victorian, three blocks from Lake Superior in northern Minnesota - and a traditional event this time of year), and was prepared to pull and bake my board, but over the weekend I defeated the transparency element as you suggested, and so far - regardless of load - not a single pixilation has occurred!

I plan to follow the progress of the MacBook Pro lawsuit, and intend to write the legal counsel pursuing the matter with an explanation of the much broader swath of Mac products experiencing similar difficulties, in the hope that perhaps they may be inclined to expande the scope of aggrieved participants...

After a few days, turning transparency off has definitely helped. It hasn't eliminated the problem, but has definitely reduced the intensity of the storms.