i even get 4k@60hz here on a rpi4 on 9front, but there was a lot of interference with bluetooth, wifi and usb3, it might be you need an extra strong signal, did you try with a short cable that has a high bandwidth?
On 3/10/21, Bakul Shah <ba...@iitbombay.org> wrote: > On Mar 10, 2021, at 8:53 AM, Richard Miller <9f...@hamnavoe.com> wrote: >>> That is, if I plug into a ~10 year old Vizio television >>> everything works fine at a reasonable resolution (1280x1024? I haven't >>> yet figured >>> out which utility to use to query display properties) >> >> Here's a simple way: >> >> term% echo `{dd -if /dev/screen -bs 64 -count 1} >> >>> , but if I plug it into a Dell >>> S2817Q the monitor says "No signal detected." >> >> That's a 4k monitor, I think. The native resolution is probably too big >> to fit in the virtual area allowed for the kernel frame buffer. (Lack of >> foresight - monitors were smaller when 9pi was first done.) >> >> I'll see about fixing that soon. Meanwhile, you should be able to use >> hdmi_group and hdmi_mode settings in config.txt to request a lower >> resolution. >> Or add something like "vgasize=1600x1200x16" to the command line in >> cmdline.txt - >> either method should work. > > Not sure how things are different in pi4+pi9 but I was able to get 4K@20Hz > under plan9 back in 2014 on the original pi. Not sure I can find that > SDcard now but the settings were based on what I gleaned from this thread: > https://www.raspberrypi.org/forums/viewtopic.php?t=79330 ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T295835c4cafb6d4f-M5444f7c46a5f07d392c4a08c Delivery options: https://9fans.topicbox.com/groups/9fans/subscription