fcapri
Posts: 13
Joined: Wed Nov 26, 2014 6:02 pm

2560x1600 resolution

Tue Jun 14, 2016 1:36 pm

hi everybody,

i have been reading a few days about my problem. i trying to connect a 30" computer monitor (HP ZR30W i think) on my raspberry. bij default it uses the resolution 1280x800 (16:10). i need to use the full resolution of the sceen.

i made some changes in the config.txt file and got it half working.
with the following settings, i have a full screen image as it should be, but al the text is blurry (like 1280x800 with very small console font is stretched to 2560x1600)

Code: Select all

hdmi_drive=1 
hdmi_group=2
#hdmi_mode=76       #this is the native settings for my display but i got a black screen with this
hdmi_force_hotplug=1
config_hdmi_boost=4
disable_overscan=1
max_framebuffer_width=2560
max_framebuffer_height=1600
framebuffer_width=2560
framebuffer_height=1600
i continued playing aroud and got i working at full screen... for about 2seconds

Code: Select all

hdmi_drive=1 
hdmi_group=2
config_hdmi_boost=4
hdmi_force_hotplug=1
disable_overscan=1
hdmi_pixel_freq_limit=275000000
on these settings i get the full screen clean resolution on the screen, and for some reason, the screen doesn't accept the resolution and turns off (like no signal).
i also can start an X server and while changing between VT01(console) and VT07 (X), the screen flikkers a little but, have 2seconds image and turns off image.
but the resolution is ok.

when booting the rpi, i also type the following in the console (without seeing anything)

Code: Select all

tvservice -s
.
after i insert the following 2 commands to have picture again

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tvservice -e "DMT 27"
fbset -depth8 & fbset -depth 16
.
then i can see in the above linse, the tvservice -s reported i'm running [email protected] progressive
and the output tells me i'm running [email protected] progressive.
this screen now looks like the first blurry one, but is a little bit more clean.
i'll try to make some pictures tomorrow

i'm convinced it is possible to run this resolution on a rpi, i just can't get it working with the correct settings.
other websites reported they run 2560x1080 on openelec. those settings (almost the same as my first config.txt code) don't work for me

stevech
Posts: 144
Joined: Sun Jul 15, 2012 11:53 pm

Re: 2560x1600 resolution

Wed Jun 15, 2016 3:30 am

I'll guess that the monitor can't do that resolution with HDMI. Rather than display port,

fcapri
Posts: 13
Joined: Wed Nov 26, 2014 6:02 pm

Re: 2560x1600 resolution

Wed Jun 15, 2016 5:10 am

the monitor can display the resolution when using an ordinairy computer. we are trying to replace those computers with raspberrys, but only if they can handle the resolution

User avatar
rpiMike
Posts: 856
Joined: Fri Aug 10, 2012 12:38 pm
Location: Cumbria, UK

Re: 2560x1600 resolution

Wed Jun 15, 2016 7:29 am

Apparently there is a pixel clock limit also :

viewtopic.php?t=20155&p=195443

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 7149
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: 2560x1600 resolution

Wed Jun 15, 2016 10:56 am

Discussion about running 4k out of the HDMI
viewtopic.php?f=38&t=79330
Either lower the framerate, or overclock.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5318
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: 2560x1600 resolution

Wed Jun 15, 2016 11:15 am

I'd suggest:

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hdmi_drive=1
hdmi_group=2
hdmi_mode=76
max_framebuffer_width=2560
max_framebuffer_height=1600
config_hdmi_boost=7
hdmi_pixel_freq_limit=268500000
core_freq=400
force_turbo=1
But we are in heavy overclock territory so no guarantees.

fcapri
Posts: 13
Joined: Wed Nov 26, 2014 6:02 pm

Re: 2560x1600 resolution

Wed Jun 15, 2016 12:51 pm

rpiMike wrote:Apparently there is a pixel clock limit also :

viewtopic.php?t=20155&p=195443
i know, i already changed the pixel clock limit to higher value. 271 000 000 is to low and doesn't give me image, 275 000 000 is ok.
dom wrote:I'd suggest:

Code: Select all

hdmi_drive=1
hdmi_group=2
hdmi_mode=76
max_framebuffer_width=2560
max_framebuffer_height=1600
config_hdmi_boost=7
hdmi_pixel_freq_limit=268500000
core_freq=400
force_turbo=1
But we are in heavy overclock territory so no guarantees.
i tryed those settings but didn't work, your pixel freq limit is to low. i changed this to 275 000 000 and then i've got image. and the image stays on, so the monitor is happy.
so what changed except overclocking? i've got the same 2 images. with my settings the monitor turns off after 2 seconds, with your settings, the monitor stays on 'somethimes flicker a lit, but keeps working. signal on the HDMI not clear?

when i'm working on 2560x1600 i got some green pixels.
i've used 3 kinds of settings as you can see on the next picture:
1) using hdmi_cvt
2) using framebuffer_height en widht
3) using the hdmi_timings command.
each of them give a little different output (framebuffer makes the tekst unreadable blurry while the other two are usable).

here a picture of a blurry screen (my phone screws up because it cannot focus)
Image
url for bigger view http://fcapri.homelinux.com/off/pics/ra ... ry4BIG.jpg

here is a picture of the clear 2560x1600 resolution on screen
Image
url for bigger view http://fcapri.homelinux.com/off/pics/ra ... 0OKBIG.jpg

and a closeup of the green pixels that are also on there
Image
url for bigger view http://fcapri.homelinux.com/off/pics/ra ... elsBIG.jpg

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5318
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: 2560x1600 resolution

Wed Jun 15, 2016 1:33 pm

You could try increasing config_hdmi_boost more. It goes up to 11.
Also try using a high quality (thick wires) short hdmi lead. The green pixels are probably caused by signal degradation caused by the higher frequency pixel clock.

fcapri
Posts: 13
Joined: Wed Nov 26, 2014 6:02 pm

Re: 2560x1600 resolution

Thu Jun 16, 2016 9:48 am

wel, hdmi_boost = 11 didn't work at all, it got even worse
Image
http://fcapri.homelinux.com/off/pics/hd ... t11BIG.jpg

but removing hdmi_boost = 11 was quite better actually. still have minimal green dots, but i'm gonna try a different hdmi cable for this (i used the cheap one that was deliverd with the rpi)
Image
http://fcapri.homelinux.com/off/pics/hd ... OFFBIG.jpg

fcapri
Posts: 13
Joined: Wed Nov 26, 2014 6:02 pm

Re: 2560x1600 resolution

Tue Jun 21, 2016 8:05 am

update on this topic, i think the rpi died.
I still have image if I connect it to a small screen (640x480, 800x600, 1920x1080..., all no problem).
the moment I connect it to the HP 30" monitor, this screen goes from orange light to blinking blue (sees the source but cannot determine the image). also tested with 2 other 30" monitors and always the same.
resolutions used 640x480 en 800x600.

we put the SD card in another rpi and this one works fine on the 30" monitors, then we put a fresh SD card from the other rpi's in this rpi and we also have no image.

our test was succesfull, the rpi is not capable of delivering 2560x1600 during long periods without problems (rpi shall not be used in our system). we will stay with our HP thin client machines

assadollahi
Posts: 21
Joined: Sun Jul 26, 2015 6:39 pm

Re: 2560x1600 resolution

Tue Jan 09, 2018 8:14 pm

btw: which raspberry pi did you use? 3? 2? orig?
just bought a 4k screen and would hate not being able to use it...

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