Can I diy upgrade base iMac (570x model) to 9900k?

[Amethyst]

I have seen some people post fixit that they unsuccessfully upgrade 570x iMac.

Is that real?

 

[nihil0]

There is a thread here somewhere that some user unsucessfuly "upgraded" i5-7600K to i7-7700K on 2017 27-inch iMac. It was simply not booting. After swapping to original i5, everything was again OK. I suppose same thing would probably most happen in your situation as well.

 

[TwoH]

It is possible to upgrade the CPU in your iMac - just take note that the swapping the processor on a Slim 27" iMac isn't as easy as a lot of other machines, and older iMacs/21.5" slims.