success with triple monitors using eyefinity and xf86-video-ati

bukwrim · 2012-01-28 04:33:38

I also have a triple head setup working - thought I'd post the details to add to the general store of knowledge.

Radeon HD 5770 using the open source driver.

One 1680x1050 monitor connected via DVI, one 1280x1024 monitor connected via DVI, and one 1280x1024 monitor connected via an HDMI to DVI cable. Apparently that last monitor's not supposed to work, but it's working fine for me - at least in Linux. It doesn't work in Windows.

Running Compiz as a standalone window manager, compositing works fine. Setting resolutions via xrandr on login. Only hiccup is that I have to set up only the 2 DVI monitors first, then run xrandr again to set up all three monitors. If I set up all three monitors right away, the second DVI monitor will only run at 1024x780 - I have no idea why.

o1911 · 2012-03-26 08:30:35

Hi there,

I'm wondering if anyone can help me- this thread appears to be the most applicable on the 'net. My T500 thinkpad has a displayport, and after trying this port with a displayport monitor and displayport cable, the screen won't work. The linux side of things appears to be fine, and thinks it is extending successfully. What is strange is that it works perfectly as expected in Windows. I'm using the latest xf86-video-ati driver, KMS and a Mobility Radeon HD 3650. The BIOS has been configured to use only the ATI card, not the intel graphics or both. Other resolutions work, just not the maximum resolution.

I understand that there was an issue of displayport not working initially, but was resolved by using a VGA adapter. Personally, I wouldn't like to convert to analogue (or pay for any adapter!), and am just wondering if there was an alternative, or perhaps a reason why I'm experiencing this.

Thanks!

gorky · 2012-03-26 11:44:43

By 'don't work' you mean it does not work in a maximum resolution or it does not work at all? Please be more verbose about what is happening.
Your xorg.conf (if any) and Xorg.0.log are also needed - please use pastebin.com to post them.

o1911 · 2012-03-26 22:50:35

Sorry if this was worded awkwardly; I did mention that all other resolutions work normally. Only the maximum resolution (1920x1080 on this monitor) does not work. Also, there is no Xorg.conf file; I'm using KMS.

edit: I just tried the same laptop, same setup with another displayport monitor. This monitor's maximum resolution is 1680x1050, and again does not work. All other resolutions do.

Last edited by o1911 (2012-03-26 23:08:05)

gorky · 2012-03-26 22:55:33

If other resolutions work normally, maybe it comes from the fact that you are trying to run the second monitor in clone mode? You will be limited to the resolution of laptop screen in such case.

Can you please post result of 'xrandr -q' ?

o1911 · 2012-03-26 23:13:18

Thanks for your persistance, gorky. I've put these details in a pastebin: http://pastebin.com/m4qzQhjd

gorky · 2012-03-27 01:56:34

OK, just to make things straight: the connected monitor had a resolution of 1920x1080, yes? And THIS monitor is reported by xrandr to have maximum supported resolution of 1680x1050, yes?
Also when you have connected a monitor with 1680x1050, the maximum resolution reported by xrandr was lower than 1680x1050 - is it correct?

If yes, than it seems like the maximum resolution is 'eaten' by something. Could you please pastebin Xorg.0.log? We should see if the screen size reported in EDID is correct. Also you have written about xf86-config-ati, but is your xorg-server also in the newest version?

If it is a bug in drivers not detecting the correct resolution, you can just force resolution using xrandr --addmode (using --newmode earlier if necessary), but it should not be needed (it is usually used rather with CRT monitors).

Last check: have you tried booting the laptop with monitor already plugged in?

Last edited by gorky (2012-03-27 01:58:06)

o1911 · 2012-03-27 10:01:24

The first monitor had a maximum resolution of 1920x1080, and did not support 1680x1050 (the next biggest resolution was 1280x1024, which worked fine with displayport). The second monitor had a maximum resolution of 1680x1050, and again the next biggest resolution was 1280x1024, which also worked fine. The monitors are very similar, apart from the obvious difference in resolution, and are both Dell brands. It appears to me that for whatever reason, either my ATI card or these monitors won't play nicely with big resolutions on linux, seeing as they work fine in Windows. These maximum resolutions also work perfectly fine using my VGA output with the same ATI card on this laptop.

Unfortunately I cannot paste the Xorg.0.log right now; I'm busy and away from the monitors. I'll do so when I can.

Finally yes, I have booted the laptop with the displayport cable in, and the external monitor will extend while booting, but fails again when KMS kicks in, as it's trying to set the maximum resolution of that screen.

edit: Oh, and I keep everything up-to-date with the standard repos, always.

Last edited by o1911 (2012-03-27 10:25:46)

gorky · 2012-03-27 10:41:36

o1911 wrote:

The first monitor had a maximum resolution of 1920x1080, and did not support 1680x1050 (the next biggest resolution was 1280x1024, which worked fine with displayport). The second monitor had a maximum resolution of 1680x1050, and again the next biggest resolution was 1280x1024, which also worked fine.

So where did the 1680x1050 resolution in 'xrandr -q' came from? It was definitely reporting an attached second monitor working at 1680x1050.

o1911 · 2012-03-27 13:04:44

gorky wrote:

So where did the 1680x1050 resolution in 'xrandr -q' came from? It was definitely reporting an attached second monitor working at 1680x1050.

This was the `xrandr -q` output from when the second monitor was attached, the one that has a maximum resolution of 1680x1050. All other resolutions worked. This `xrandr -q` output has nothing to do with the monitor prior (with 1920x1080 resolution), excepting that neither worked on maximum resolution.

gorky · 2012-03-27 13:12:26

According to what you have pasted, the attached monitor was working at 1680x1050.

Whereas xrandr not reporting correct resolution is something that happens from time to time, I have never seen a case where the reported working resolution was different than the real one.

Could you post a result of xrandr -q with the 1920x1080 monitor attached?

BurntSushi · 2012-03-29 02:08:26

@o1911 - I really have no idea how to fix your problem, but reading through your process sounds eerily similar to the process I went through in the OP with the DisplayPort adapter. Nothing I tried worked, and the xrandr output didn't make sense either. I even tried gorky's suggestion of adding a mode manually. No dice.

I didn't ever get a chance to test it with Windows, so the fact that it's working for you there may or may not be related. Maybe there's a problem with the way the DisplayPort -> DVI adapter is read with the driver that doesn't occur with DisplayPort -> VGA. But then again, I had this problem with both the open source and proprietary drivers...

You may want to at least try a DP -> VGA adapter if you're willing to live with it if all else fails.

o1911 · 2012-03-30 00:51:30

gorky wrote:

According to what you have pasted, the attached monitor was working at 1680x1050.
Whereas xrandr not reporting correct resolution is something that happens from time to time, I have never seen a case where the reported working resolution was different than the real one.
Could you post a result of xrandr -q with the 1920x1080 monitor attached?

As I started in my first post, yes, linux thinks it is extending according to xrandr, but I can tell you that the monitor doesn't actually work at that resolution. Hence my original definition of the problem. I won't have time to post `xrandr -q` with the 1920x1080 for a week, but it's output was much the same.

@BurntSushi - thanks for your input. I fear I may have to give an adapter a try... sucks, but it's an extra interface. I just wondered if someone knew a reason or I missed something.

gorky · 2012-03-30 09:05:15

Ah, OK. You were quite brief in the first post and so I needed to confirm those things.
In this case it looks like a bug.

Could you try using vesa driver to check if it is a bug in drivers or in randr?

o1911 · 2012-03-31 07:05:39

gorky wrote:

Ah, OK. You were quite brief in the first post and so I needed to confirm those things.
In this case it looks like a bug.
Could you try using vesa driver to check if it is a bug in drivers or in randr?

I'll give it a try when I can, could be a while.

Arch Linux

#51 2012-01-28 04:33:38

Re: success with triple monitors using eyefinity and xf86-video-ati

#52 2012-03-26 08:30:35

Re: success with triple monitors using eyefinity and xf86-video-ati

#53 2012-03-26 11:44:43

Re: success with triple monitors using eyefinity and xf86-video-ati

#54 2012-03-26 22:50:35

Re: success with triple monitors using eyefinity and xf86-video-ati

#55 2012-03-26 22:55:33

Re: success with triple monitors using eyefinity and xf86-video-ati

#56 2012-03-26 23:13:18

Re: success with triple monitors using eyefinity and xf86-video-ati

#57 2012-03-27 01:56:34

Re: success with triple monitors using eyefinity and xf86-video-ati

#58 2012-03-27 10:01:24

Re: success with triple monitors using eyefinity and xf86-video-ati

#59 2012-03-27 10:41:36

Re: success with triple monitors using eyefinity and xf86-video-ati

#60 2012-03-27 13:04:44

Re: success with triple monitors using eyefinity and xf86-video-ati

#61 2012-03-27 13:12:26

Re: success with triple monitors using eyefinity and xf86-video-ati

#62 2012-03-29 02:08:26

Re: success with triple monitors using eyefinity and xf86-video-ati

#63 2012-03-30 00:51:30

Re: success with triple monitors using eyefinity and xf86-video-ati

#64 2012-03-30 09:05:15

Re: success with triple monitors using eyefinity and xf86-video-ati

#65 2012-03-31 07:05:39

Re: success with triple monitors using eyefinity and xf86-video-ati

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