Contribute
Register

6850 and 6870, DisplayPort garbled on reboot

Status
Not open for further replies.
HoosierInFL said:
akasurreal said:
HoosierInFL said:
I had this problem. I was using the Accell adapter that is certified by ATI. I then replaced it with the Apple branded one and the problem went away completely.

Interesting, everything I have read says Apple's adaptors are passive (not Active) and therefore do not work on ATI cards. I tried one and it actually does work, BUT, it auto disables my second monitor plugged into HDMI whenever I plug it in, so it does me no good.

Yes, I have read that you can't do mini display port and HDMI at the same time on these cards. I am running 3 monitors. Two via mini display port and one via hdmi.

Well you can actually, because I am doing it and have read others that are. If I use the passive Apple Adaptors though, I can never do more than 2 monitors because it keeps disabling both my DVI & HDMI ports. Also, just keep in mind, none of these problems appear in Windows boot on same machine, so its definitely a software related issue.
 
akasurreal said:
straycat264 said:
I don't know if this is of any use... but I'm currently running two Samsung 2443BWs at 1920x1200 and an old 20" Aluminium Cinema Display at 1680x1050 on my 6870

The strange thing is that if I plug either of the Samsungs in via a DP, they display the exact behaviour you describe - but the Cinema Display doesn't - it works perfectly.

At the moment, this isn't a problem, but I'm planning to add another 1920x1200 into the mix, and pass on the Apple display to my partner, so it'll become an issue at that point.

Do you multi-boot Windows and notice this same behavior there? Because on my system, under Windows, everything works as expected, its only OSX. I will try a different monitor though to see if that changes anything.

Learned something new!

So tried another 24" Samsung and nothing changed. I don't have a cinema display to test, but I did notice something else that may explain why it worked for you. If I set any of my displays to less than 1920x1200, it survives a reboot just fine on DP. So it seems to have something to do with using the max resolution. I would never run a LCD at less than native, as it looks horrible, but it may give a clue as to what's happening here.

Edit: Has anyone else gotten a third monitor running at 1920x1200 on Display Port to come up on reboot without this problem? Luckily I can fix it fairly easily after each reboot but would be nice to not need to.
 
akasurreal said:
akasurreal said:
straycat264 said:
I don't know if this is of any use... but I'm currently running two Samsung 2443BWs at 1920x1200 and an old 20" Aluminium Cinema Display at 1680x1050 on my 6870

The strange thing is that if I plug either of the Samsungs in via a DP, they display the exact behaviour you describe - but the Cinema Display doesn't - it works perfectly.

At the moment, this isn't a problem, but I'm planning to add another 1920x1200 into the mix, and pass on the Apple display to my partner, so it'll become an issue at that point.

Do you multi-boot Windows and notice this same behavior there? Because on my system, under Windows, everything works as expected, its only OSX. I will try a different monitor though to see if that changes anything.



Learned something new!

So tried another 24" Samsung and nothing changed. I don't have a cinema display to test, but I did notice something else that may explain why it worked for you. If I set any of my displays to less than 1920x1200, it survives a reboot just fine on DP. So it seems to have something to do with using the max resolution. I would never run a LCD at less than native, as it looks horrible, but it may give a clue as to what's happening here.

Edit: Has anyone else gotten a third monitor running at 1920x1200 on Display Port to come up on reboot without this problem? Luckily I can fix it fairly easily after each reboot but would be nice to not need to.

I have a 5770 on 10.6.7 and have x 2 DVI with 1920 x 1080 and 1 x DP with vertical 1920 x 1200. Lose DP in 10.6.8. Not sure if that helps you or not.
 
akasurreal said:
Do you multi-boot Windows and notice this same behavior there? Because on my system, under Windows, everything works as expected, its only OSX. I will try a different monitor though to see if that changes anything.

Heh. I wish I could answer that, but my hack will no longer boot into Windows, and I've given up trying to figure out why not (XP just bluescreens on me, and W7 install discs just hang on boot.) There's something strangely ironic about this...

This, btw, is nothing to do with the gfx card, or the problem at hand. It did the same with my old pair of 9800GTs.
 
Hmm, so I guess I will just deal with this issue for now, maybe Lion drivers will make a difference.
 
straycat264 said:
akasurreal said:
Hmm, so I guess I will just deal with this issue for now, maybe Lion drivers will make a difference.

Just tested it in Lion on my 6870. Not fixed - I still get exactly the same problem.

Thanks for the update. I assume you are testing on a monitor at 1920x1200? I am thinking of switching to some new 1920x1080 monitors and thinking if I am under the max I may not see this problem. Will update when they show up.
 
akasurreal said:
straycat264 said:
akasurreal said:
Hmm, so I guess I will just deal with this issue for now, maybe Lion drivers will make a difference.

Just tested it in Lion on my 6870. Not fixed - I still get exactly the same problem.

Thanks for the update. I assume you are testing on a monitor at 1920x1200? I am thinking of switching to some new 1920x1080 monitors and thinking if I am under the max I may not see this problem. Will update when they show up.

I am, yes. Still working fine on the 1600x1050 Cinema Display - it's just when I start up with the 1920x1200 display on DP that the problem manifests.
 
Found a fix!!!!!

Actually - that might be a touch premature, but I'm hopeful.
Anyway - it's worked perfectly for two consecutive boots - one cold, and one a reboot, so I'm hopeful.

Easy too.

I just set the resolution in com.apple.Boot.plist in /Extra:

<key>Graphics Mode</key>
<string>1920x1200x32</string>

Anyone having the same issue fancy giving it a go?
 
straycat264 said:
Found a fix!!!!!

Actually - that might be a touch premature, but I'm hopeful.
Anyway - it's worked perfectly for two consecutive boots - one cold, and one a reboot, so I'm hopeful.

Easy too.

I just set the resolution in com.apple.Boot.plist in /Extra:

<key>Graphics Mode</key>
<string>1920x1200x32</string>

Anyone having the same issue fancy giving it a go?

Wow, I will give that a shot in a few, thanks. Does that set it for all monitors, or do you specify per monitor somehow?
 
Status
Not open for further replies.
Back
Top