Mac Pro, 3 screens, problems!

[The-Pro]

How you doing people

I have a 2009 2.26 8-core Mac Pro with 2 GT 120 GPU's. I have a 30" ACD connected to the GT 120 in slot 1 (through DVI) and two Acer X233H connected to the other GT 120 in slot 2 (one direct through DVI other through MDP to DVI adapter). 30" in the Middle with an Acer on either side.

I have lots of very annoying things going on:

1. When I drag any window from the 30" to an Acer it stutters really badly. Once the window is fully displayed on the Acer its smooth again.
2. Occasionally I get severe graphics artifacts, where the colours become pale-ish and and very pink. This on the Acer screens. Only a reboot makes them go away.
3. When I am watching a video, on the internet, DVD, or in Quicktime/VLC/Adobe Media Player its weird aswell. When I press fullscreen, on the video, it enters full screen and all is fine. However, when for example I only want to watch the video fullscreen on the 30" without disturbance/light from the two acer screens, I turn them off. The video then stutters horribly until the screens are turned on again.

Other things to note: I have the nVidia CUDA driver installed and my Mac Pro was refurbished when I bought it in 09. Apple Hardware test was run through several times and hasn't found anything. I have reseated the GT 120's several times and also switched them around. No difference. I noticed about a year ago that the GT 120 in slot 1 was only running at 8x speed. I reseated it and then it was x16

Does Anyone know why I am having these problems? What can solve my problems apart form buying a new GPU? How can I test the GT 120's to make sure they are running fine? Does anyone else run 3 or 4 screens of two GT 120's and doesn't or does have similar problems?
Ive dealt with these problems for over a year now and they are really starting to get on my nerves

Cheers

 

[Neodym]

1. When I drag any window from the 30" to an Acer it stutters really badly. Once the window is fully displayed on the Acer its smooth again.

The Mac has to copy the graphic data from one video card to the other. This impacts the smoothness, even more so as your video cards are not the fastest ones.

2. Occasionally I get severe graphics artifacts, where the colours become pale-ish and and very pink. This on the Acer screens. Only a reboot makes them go away.

Which is it - artifacts or pale/pink colours? Artifacts would indicate problems with the graphic card going bad, while pale/pink colours sound more like a bad cabling - try to use a different cable for starters.

A general comment: I had problems with EyeTV starting to stutter while i had connected two screens to my 7300GT (which admittedly only has 256MB VRam). Since i am only running one screen off the 7300 and the other two off the 6870 (1GB VRam), i'm fine.

As you are running two limited graphic cards, you could try to borrow a friend's 5770 or 6870, replace either GT120 for testing purposes (they run ootb under 10.6.8+, though you can't run Apple DVD player directly) and see if the problems persist.

 

[The-Pro]

The Mac has to copy the graphic data from one video card to the other. This impacts the smoothness, even more so as your video cards are not the fastest ones.

Thats what i guessed is whats causing it. Its just that when moving windows on my dual 1GHz MDD G4 from one screen (connected to ATI 9800 pro) to the other screen (connected to ATI Rage 128) it doesn't stutter at all.

Which is it - artifacts or pale/pink colours? Artifacts would indicate problems with the graphic card going bad, while pale/pink colours sound more like a bad cabling - try to use a different cable for starters.

Well its weird what it does. Its like a combination of the two. You cant read the texts because they are all funky and the colours arre pinkish. Its not artifacts normal artifacts. Also if I move the windows that has these weird colours it becomes normal when moving it and then changes to the weird pink stuff and manky texts once I stop moving it. The background of the dock also has pink pixel lines and blocks in between the dock icons. So its actually on all screens, (30": dock, and the Acers: the others stuff)
It hard to explain really, sorry. Ill try and get a picture of it tomorrow if it happens again but its quite random and sometimes doesn't occur for days.

A general comment: I had problems with EyeTV starting to stutter while i had connected two screens to my 7300GT (which admittedly only has 256MB VRam). Since i am only running one screen off the 7300 and the other two off the 6870 (1GB VRam), i'm fine.

As you are running two limited graphic cards, you could try to borrow a friend's 5770 or 6870, replace either GT120 for testing purposes (they run ootb under 10.6.8+, though you can't run Apple DVD player directly) and see if the problems persist.

Interesting.
In the next weeks I can try and get the 5770 out of my other MP, its at a different location though, and test it that way.

Ever heard of the thing I mentioned with video stuttering on the 30" when the two Acers are turned off??

Cheers

 

[Neodym]

Thats what i guessed is whats causing it. Its just that when moving windows on my dual 1GHz MDD G4 from one screen (connected to ATI 9800 pro) to the other screen (connected to ATI Rage 128) it doesn't stutter at all.
[...]
Ever heard of the thing I mentioned with video stuttering on the 30" when the two Acers are turned off??

No - sorry! Might be a driver problem, as Apple has focused on AMD/ATI over the last few years. Did you try (just for fun) to place the second GT120 in Slot 3 or 4? Even though those are only x4 slots - maybe the two x16 slots (1 and 2) are somehow related and (together with a faulty driver) produce the effect(s) you describe?!

 

[The-Pro]

No - sorry! Might be a driver problem, as Apple has focused on AMD/ATI over the last few years. Did you try (just for fun) to place the second GT120 in Slot 3 or 4? Even though those are only x4 slots - maybe the two x16 slots (1 and 2) are somehow related and (together with a faulty driver) produce the effect(s) you describe?!

Was thinking about doing that. Ill try it in the morning. GT 120's are so slow, they probably don't even saturate the x4 slot. Which is probably why apple advertised you can connect 8 x 30" ACD for a wall of screens with the 2009 MP through 4x GT 120's.
Sounds possible
Is there a way to reinstall the drivers if it turns out to be the case?

 

[Balders]

If you have calibrated the screens colours, have u tried setting them to the default colour profiles? Seen weird things happening after setting colour profiles previously... Worth a try...

B

 

[The-Pro]

Well I have tried out the two GT 120's in all sorts of configurations. Slots 1+3, 1+4, 2+3, 2+4, 3+4. Sadly with all of them I still got the stuttering of video when other screens are turned off.
The screen problems haven't occurred yet so I dont have a picture of it.

@Balders
I have set the Acers to portray similar colours than that of the ACD. I put them back to default and no difference

I was thinking, I need the CUDA driver for my work (Octane Render etc), can these drivers have screwed something with the system?

Is there a GPU hardware test available?

 

[BrianBaughn]

I had a customer recently with the same two GT 120 cards, a three monitor setup, running 10.6.8 and video weirdness that suddenly appeared.

I installed the drivers from here and he hasn't had any problems for the last two weeks.

 

[The-Pro]

I had a customer recently with the same two GT 120 cards, a three monitor setup, running 10.6.8 and video weirdness that suddenly appeared.

I installed the drivers from here and he hasn't had any problems for the last two weeks.

Cheers mate

I installed the drivers and did a quick test. The stuttering when the other screen are off still persists.
I dont know about the colours and weird text things. Its totally random when it occurs so ill have to be patient and see if it happens.

Can CUDA drivers have affected something?

 

[BrianBaughn]

Cheers mate

I installed the drivers and did a quick test. The stuttering when the other screen are off still persists.
I dont know about the colours and weird text things. Its totally random when it occurs so ill have to be patient and see if it happens.

Can CUDA drivers have affected something?

I don't know. He definitely doesn't have the CUDA drivers installed, though.

 

[The-Pro]

I don't know. He definitely doesn't have the CUDA drivers installed, though.

Ah ok. Thank you
im going to carry on experimenting. Maybe I will find something.