Am Sonntag, 22. Juni 2014, 00:51:55 schrieb Thomas Richter: > Hi Martin, Hi Thomas, > >> I'm trying to figure out how to ask X what color depth it is using...? > > > > I think: > > > > martin@merkaba:~> xdpyinfo | grep -i "depth of root" > > > > depth of root window: 24 planes > > > > but am not completely sure. > > > >> This is thinkpad x60 with Debian 6.0.9. > > AFAIK the 830GM chipset does not offer any support for hardware > dithering. Whether the panel in the x60 does I do not know, though. > > However, what is remarkable is that graphics on a 16 bit(!) screen may > look more pleasing than graphics on a 24 bit screen, at least for such > ancient machines. The reason is that the panel cuts the bitdepth down > from 8 to 6 bits, without any dithering, just by cutting off the LSBs. > However, if you select a 16bpp mode to begin with, some desktop > environments (specifically gnome) apply a dithering of their own, even > though the output is only 5 bit per component. > > This is at least what I see here on the IBM R31 and the Fujitsu S6010: > Gnome desktop at 16bpp looks better than the desktop at 8bpp, due to the > lack of hardware dithering. > > The X11 intel driver had an option "Dac6Bit" to signal the 6 bit panel > resolution to X (even though the display pipeline operates in 8 bit > mode), but I have never seen this working in the past time. It seems not > to be supported anymore. Probably that's the culprit. > > Martin, you should probably test Ville's alm_fixes5 kernel branch, its > support for the 830GM chipset of the X30 is in my experience much better > than that of the drm-intel-nightly or official kernels. I didn´t report this. I just mentioned how to find out the screen depth. Pavel reported this. On my ThinkPad T42 I do not compile own kernels anymore and on this ThinkPad T520 I will wait till 3.16-rc2. Thanks, -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
