Here are mine:
Note: This is my rig
OS: Windows 10
CPU: AMD Ryzen 7 3700X 8-Core Processor 3.60ghz
GPU: AMD Radeon RX 5700 XT
RAM: 16.0 GB DDR5
Those setting enable me to max out all NBA 2K PC titles, including 2K21, in 1080p and even 4k in combination with my rig. I upload some of the gameplay to youtube, so you can see from the videos that it is smooth.
I have never had to adjust my adrenalin settings for any of the past titles, either. I have all the 2Ks on PC going back to 2K9, and all work great with those settings. Our setup is a bit unique, because we are playing on a 50 inch TV and using Xbox One Wireless Controllers. Basically, we have our computer setup like a console in our living room.
Hopefully this info helps!