I wouldn't recommend the DTP94 at this point because it was developed in the days of CRT and standard-gamut LCD monitors with CCFL backlight, e.g. it doesn't have correction tables for white LED which is the most common backlighting technology these days.
dispcalGUI can do uniformity...
That's a decent test image, I'm using it as well.
It probably isn't.
That alone won't be enough. The banding you're seeing is a compound effect of all the things I mentioned above.
Not a good test if you want to look at videoLUT banding, for those reasons:
- The Spyder5 software introduces banding by quantizing the calibration values to 8-bit ('vcgt' with entrySize = 1, which means 8-bit), before they get even written to the videoLUT.
- Game scenes are a result of...
Note that a 10-bit monitor does nothing for gaming (unless it has an internal LUT that can be used by calibration software), and you need a Quadro card.
Not recently, some years ago (I can confirm for my GTX 465, for example). Most modern AMD/nVidia cards seem to operate like this (assuming 8 bit connection to display):
Linear videoLUT:
Compositor -> 10-12 bit 1D videoLUT -> 8-bit output
Non-linear videoLUT:
Compositor -> 10-12 bit 1D...
Not via the driver, but e.g. ReShade (if it supports the specific game) can be used to apply custom LUTs for full gamut correction, so you're not even limited to whitepoint/grayscale like via the graphics card 1D curves.