I've been following this thread for nearly 2 years, and I think I understand Ausdauersportler's feelings. The experts have been working very hard to come up to solutions. They have explained every details, picking up from each and every useful informations scattered all over the posts of this 6-hundred-ish-page thread. There maybe some language barriers to some, but by reading and understanding post #1 and every link from post #1 with the help of Google translate, even a novice Mac user (like me) can do the upgrade. When hitting an issue, you just need to come to this thread, using the search function with several key words, and you will see similar cases have been described with solutions already.
A simple price search of the cards listed on post#1 will give you a glimps of what to buy, how powerful it would be, etc.
But instead of reading, more than half of the new comers to this thread often start with: "What is the most powerful card to go with my 2009~2011 iMac, which I've just got for free, blah blah blah etc.". And those attitudes are really disgusting. We are only try to make old iMacs (more often than not, with dead GPUs because of Apple's design flaw) work again and upgradable to newer Mac OS, keeping them from going to metal scrap yard, while pulling some usage from them.
If money doesn't matter, discuss your concern with the GPU sellers from the Far East, they have the responsibility to help you with your issue to sell their merchandise and benefit from that. They read this thread, too.
