I have a Lenovo ThinkPad X13 (AMD) which I purchased recently, with the touchscreen option (AU Optronics B133HAK02.2). Based on information on the net, this model is ostensibly a 8-bit panel (or perhaps 6-bit FRC?).
In either case, normally, I would expect Windows to report the panel as being a 8-bit panel (it does so for my Dell U2417H when connected to the laptop, even though it is a 6-bit FRC panel). However, I noted that Windows shows the bit depth as 6-bit color when I go to "View advanced display options". There does not seem to be any option to toggle 8bpc in the Radeon Settings control panel (I have downloaded the latest drivers just to be sure).
Initially, I thought "okay, maybe this is just a reporting error, or perhaps this is how AMD reports it to Windows", but this classification as a 6-bit panel seems to have some repercussions. Namely, whenever I view a solid, dark-coloured background (e.g. grey), the solid colour instead appears noticeably grainy, much like a JPEG or MPEG compression artifact. I suspect it is the graphics driver trying to dither the colour (in a very poor manner).
For a while, I was resigned that this is a permanent characteristic of my panel and I would just have to deal with it. However, I got an idea today to boot up to an Ubuntu live CD, and lo and behold! I did not notice any dithering artifacts there and all my solid colours appear, well, solid. I went to the store to test a ThinkPad X13 (Intel version) with the same display panel and it also displays solid colours properly.
Thus, I am inclined to think that there is a bug in the current AMD drivers and that the panel should be reported as an 8-bit panel (and perhaps, if it's 6-bit + FRC, let the monitor do the dithering on its own?). Is there any way this issue could be looked into? Is there also a way to force AMD to display 8-bit colour in Windows and stop dithering my colours?
I am not sure if I have posted in the correct forum, but since there is no laptop forum over here I thought this would be the most appropriate place to post.
Thanks so much!