Just to add to this in case anyone else encounters the same problem. I had banding that almost appeared vector like in photoshop cc 2017 when using any brush much like the problems encountered in this thread. Luckily I have a dual monitor setup with a 27" LG IPS and a 24" Dell IPS. What I did was drag the file from photoshop from my main LG into the Dell and noticed that the gradients all appeared perfect. That led me to believe that it wasn't the video card or photoshop necessarily causing the issue. It turns out that the monitor profile is what caused the banding. I calibrated the monitor using a calibrator which created a monitor color profile. I loaded this in windows 10. Now the important part. In photoshop under edit > color settings you have to choose that same color profile used in the monitor. When both are the same profile the gradients all magically worked again. Hope this helps
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