El Capitan iMac (late 2009) Major Graphics Issues

I don't want to sound like a downer, but if all of your Apple software is working fine, these are issues with the third party software.

It is the job of the third party developers to make their software work with El Capitan; it is not Apple's job to make the OS work with other software.

Since all of the software you mentioned is third party, checking to make sure sure you have all of their necessary updates and drivers is the first step to fixing these issues. I know it's easy to blame El Capitan, and yes these issue didn't happen until it was installed, but there is a reason developers can access OS betas and tools before they are released. It is the developer's responsibility to make their apps work with current software.

A lot of people blamed Apple in 2010 when Quciken 2007 didn't work in Lion. Curse Apple for not making sure a 3 year old, third party software wasn't going to work flawlessly in their new software. Do you know what Quicken's response was? Buy the new software. If the third party doesn't put out updates for their software to work, it is not the fault of Apple.

Your best bet is to look into the support forums and support pages for each individual software. If all the Apple software works as expected, then the problem is third party.

If you have a Time Machine backup, you can restore your computer back to it's previous version until the software developers put out a fix.

Best of luck

FFinally restoring from backup- wasted afternoon trying to restore- now going to take 20 hours to restore files!

do not recommend the upgrade! Just hangs every time and freezes at 20 minutes

what are you seeing in Modo? I'm running Blender (you can make fun of me later) and it's smooth with my ATI card on my 2010 Dual Xeon.

If a problem can be identified Apple might be inclined to look at it but for the most part Apple writes their own GPU drivers and back in July a serious issues with OpenCL was identified by a developer writing a bridge application to LuxRender. It was reported it to Apple and after months of no response Apple finely wrote back they would "fix it", this was during the lifespan of 10.10. but as of 10.11.1 it is better, but still not entirely fixed according to developers there and at the Blender foundation.

I agree with you. Unfortunately Apple's secrecy seems to hurt it's customers in cases like this.

If you have a Time Machine backup, you could always restore your computer to get things working again and just keep your eyes open for updates that will allow all of your software to work with El Capitan before you update again.

Best of luck

part of the issue may have been Win 10 and 10.11 were around about the same time, both were available to developers long before they went public. Developers may have been putting all their effort into Windows 10. I don't know how smooth 10 is or isn't I only know I pulled the plug on it when I read in forums a lot of production software suffered under it and video driver problems were rampant - again, what I read, not what I experienced and I'm stick with win7 until further notice.

I have the same issue and I believe it started a week or 2 ago. It looks like a problem on OSX. It was so bad for me that I decided toreinstall after trying safe mode.

NOw I can't reinstall El Capitan or Yosemite as during the installation when the process to setup voice over will have menus and dialogs that I can't see a thing.

THis his looks like there was an update to the display drive and Late 2009 iMac are seeing issues.

Im trying to restore a backup from a month ago but I'm not very optimistic.

Please Apple fix this ASAP.

Did you try baking your card? I have tried today and it worked for me.