iMac 20.1 i5 3.3 GHz to i9 10900K upgrade

Your current CPU:

• i5-10600

And the CPU's in question here:

• i9 10900K
• i9 10850K

Whats important is the product family as Apple limits its system firmware to the given family, here all three are Comet Lake so thats good and they all have the same socket. While there is a Heat Sink notation as needing a more aggressive cooler you should monitor your systems thermals to make sure you aren't over doing it After Effects can push your system a bit hard if you let it. I would recommend installing a good monitoring app like TG Pro it also allows you to log your thermals over time so you can graph things out.

So while the specs shows this chip is workable, I haven't tried installing the i9 10900K. Most of my graphics clients have moved on to the Mac Studios (wanting bigger displays)! Only the music and students are still using the iMac's and its been a few years since I've done an Intel CPU upgrade and at the time I was installing i9 10850K CPU's.

Also be aware this is a tricky CPU to get in as the springs are quite strong and seating it properly can also be tough!

Don't over do the thermal paste as you'll have issues if it gets into socket. To get an idea how much take a thin sheet of tissue the size of the heat spreader wet your fingers and roll it into a tight ball thats even a bit too much!

Do let us know how it goes!