The graphic card of my 2011 imac died and i have found an ati raedon 4670 from an iman 2009 for cheap but i dont know if it fits
iMac 27", macOS 10.13
No, they do not. If you need to replace the GPU for a 2011 iMac you need to locate a 2011 GPU. As these models have been considered obsolete for many years finding one may be difficult. I would recommend replacing the computer with a more current Mac.
Aside for all the other reasons why this probably would not work, what happens when the motherboard or power supply borks due to your electrical transgressions? That is not an impossibility with an eleven year old iMac. Bury it with dignity, and purchase as recent of used iMac as your budget will permit. Something recent enough that it will get you browser and security updates from Apple because it supports current operating systems.
You may find some reconditioned ones at macofalltrades, macpartsonline, or powerbooksmedics, but those come with limited warranties and may only last for a short time.
Personally I concur with rk87 and would replace the iMac instead of spending any money or time on it.
Does an imac 27 inch 2009 graphic card work on an imac 27 inch 2011
