On Fri, Sep 19, 2014 at 02:22:49PM +0200, Tony Sarendal wrote: > Good afternoon, > > Friday question: > Does anyone have recommendation on graphics hardware to use for 4k screens > and OpenBSD ? > > I'm thinking about improving my workstation. I run lots of terminal > windows, a web browser, > and the default window manager. As I like eye candy I may even do "xsetroot > -solid black". > > What I want is a stable work environment where I can reboot my workstation > every > 6 months or so. This with a 4k screen. Doable ?
The short version is it won't work yet, the longer version is you should carefully check what the graphics hardware, monitor and software support. For Intel the HDMI 4k at 30 Hz modes are only supported on Haswell, ie i[357]-4xxx. On the AMD side HDMI 4k at 30 Hz modes are only supported on Southern Islands parts according to http://xorg.freedesktop.org/wiki/RadeonFeature/ which are Radeon HD >= 77xx. The Southern Islands parts are best avoided as xf86-video-ati only supports 2D acceleration via Glamor-EGL which on Southern Islands radeons requires a Mesa driver that has a hard requirement on LLVM, working EGL drm platform, and other things. And the kernel only knows about the initial round of Southern Islands parts, not all of those that were later released including the newer integrated graphics with Kaveri. It seems it should be possible to use 4k modes with displayport on Northern Islands/HD6xxx if the screen was presented as two smaller screens via MST as Northern Islands radeons support displayport 1.2 and MST. This isn't an option for older Intel parts as ivybridge for example only supports displayport 1.1 with no MST. The HDMI 1.4 4k modes make use of a CEA vendor extension in the blob of data from the display that describes the modes (EDID). Support for that was added in drm 3.12. Many of the 4k displays present themselves as multiple displayport displays/streams, support for that was added in drm 3.17. OpenBSD has roughly drm 3.8.13.28 at the moment. hdmi 1.4, drm 3.12 3840x2160@30Hz 3840x2160@25Hz 3840x2160@24Hz hdmi 2.0 4k @ 60Hz, drm ? displayport 1.2 4k 30Hz single stream transport (SST), drm 3.12? displayport 1.2 4k 60Hz multi stream transport (MST), drm 3.17 displayport 1.? 4k 60Hz single stream transport (4K60 SST), drm ? displayport 1.? dell 5k 5120x2880@?, MST? drm ?
