Wanting to upgrade GPU on 2014 iMac 21.5in but don't know where to start

I've been getting into using Blender, and have been suffering a lot of lag and ultra slow render times, so I've been wanting to get a GPU upgrade, but it seems to be unnecessarily difficult to do. About 95% of the info seems to be pertaining to Macbooks instead of iMacs, and the external gpus I've looked at have been either ridiculously expensive and/or are only housings.

routerloginHas anybody done this? Any suggestions for hardware? I love Mac OS, but it's times like these that I fucking just hate having an Apple computer.

Any help would be much appreciated!

192.168.0.1

You can't

You have just canceled your only option right there