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K_Rek Author

Level 1

5 points

Mid 2011 iMac Graphics Problems with Yosemite

I have a 21.5-inch, Mid 2011 iMac with an AMD Radeon HD 6770M 512 MB that is locking up on me constantly since installing Yosemite. Every time I reboot (which I have to do by pressing the power button on the back) it says that it has detected a graphics problem and do I want to report it. I have done that multiple times, but want to find out if anyone else here is having a similar problem. What appears on the screen are pixelated blocks in random areas and often the machine will work for maybe three or four minutes and then just lock up completely. It worked like a champ with 10.9.5 and previous, but 10.10 is wreaking havoc on my computer.

I have seen discussion threads about 27-inch iMacs that were recalled due to an AMD graphics chip problem, but haven't seen anything about the 21.5-inch machines. At the time, this was the highest-end card I could get in the 21.5-inch display.

The machine has 8GB of 1333 MHz DDR3 RAM.

iMac, OS X Yosemite (10.10)

Posted on Oct 21, 2014 5:58 AM

229 replies

babowa

Level 9

78,429 points

Sep 29, 2015 9:46 PM in response to Stevescrumbs

I haven't heard of anyone else in the beta testers try it out on a machine that had this issue but hope that some people report their experiences before I upgrade.

Unfortunately, betas cannot be discussed here and anyone testing would be violating their NDA if they did.

Sep 30, 2015 4:41 AM in response to K_Rek

Well today is when the final code gets released so hopefully someone will be able to discuss performance on 2011 iMacs after today. I'd like to upgrade but don't want to make things worse than they already are. I'd like for this machine to last me at least another 6 to 8 months before I can upgrade.

Dec 3, 2015 7:46 AM in response to enricoclaudio

This worked for me... perfect such a simpel fix :-)

Dec 4, 2015 6:29 AM in response to marcelkraan

I have the same graphic problem as everyone else here. Mine progressed and became worse though. Some parts of my screen would appear fuzzy and text showed slightly broken up. The computer started rebooting every few hours on it's own. I've replaced the computer and will be taking the old one to the shop soon. I anticipate a new video card but will post back when it is all said and done.

Mid 2011 iMac Graphics Problems with Yosemite