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5870 Problem

S

strausd

macrumors 68030
Original poster
Jul 11, 2008
2,998
1
Texas
So I just got my 12-core MP, yay!

However, I am trying to run an ACD 24", dell u2311h, and my tv at the same time. When I have all of them plugged in, the dell u2311h won't come up with anything. But when I unplug the tv form the MP, the u2311h comes up. Its like it can only run a max of 2 monitors. Is there a way to fix this?
 
You have downloaded all the updates, right? Do you have a third monitor to try it with? TVs can be troublesome as a monitor so I would with another monitor. Also, a call to Apple won't hurt, at least they will acknowledge this issue then
 
strausd said:
So I just got my 12-core MP, yay!

However, I am trying to run an ACD 24", dell u2311h, and my tv at the same time. When I have all of them plugged in, the dell u2311h won't come up with anything. But when I unplug the tv form the MP, the u2311h comes up. Its like it can only run a max of 2 monitors. Is there a way to fix this?
Click to expand...

maybe you need an active mini display > dvi adapter ?
 
skiffx said:
maybe you need an active mini display > dvi adapter ?
Click to expand...

Yes, if you have 2 displays that are DVI, one of them will have to use an active mdp > dvi . . . kind of lame since they are $100 each. That is if you want to use all 3 ports. I do, so I need to pony up the adapter, or stick with my 2600xt :(
 
ACD is MDP, TV is HDMI to MDP, and dell u2311h is single link DVI. The second I plug in the tv to the computer, the dell goes blank.
 
ioreg -l -w0 > ~/Desktop/ioreg.txt

up the file and we will see how much display devices u got in ioreg.
 
strausd said:
ACD is MDP, TV is HDMI to MDP, and dell u2311h is single link DVI. The second I plug in the tv to the computer, the dell goes blank.
Click to expand...

maybe hdmi to mdp isnt considered a native mdp device thus you need that active adapter.
Anyway help out netkas, he will definitely help you in return:)
 
strausd said:
So I just got my 12-core MP, yay!

However, I am trying to run an ACD 24", dell u2311h, and my tv at the same time. When I have all of them plugged in, the dell u2311h won't come up with anything. But when I unplug the tv form the MP, the u2311h comes up. Its like it can only run a max of 2 monitors. Is there a way to fix this?
Click to expand...

You may be running into this issue:

http://support.apple.com/kb/HT4279?viewlocale=en_US

Are you using the Dual-Link DVI adapters?
 
its only a 23 inch monitor, no dual link. I am using the cable that came with the monitor. Everything works perfectly. Once I plug in the tv that is HDMI to my MP via a MDP adapter, my dell monitor goes blank and it shows the TV. But it recognizes that they are different displays.
 
netkas said:
ioreg -l -w0 > ~/Desktop/ioreg.txt

up the file and we will see how much display devices u got in ioreg.
Click to expand...

did that, do you want the text file as an attachment on here?

What did that actually do by the way? Did it move something to my desktop? Copy it to my desktop? Is that gonna cause any problems?
 
strausd said:
did that, do you want the text file as an attachment on here?

What did that actually do by the way? Did it move something to my desktop? Copy it to my desktop? Is that gonna cause any problems?
Click to expand...

it saved output to file on your destop.

put it as attachment.
 
xispec said:
That's got to be crazy. To be able to use 3 DVI outputs, you'll need to use two dual link dvi adapters from MDP..... -100x2
Click to expand...

EXACTLY. I just figured that out myself. To use three monitors on the new Mac Pro, you must use TWO dual-link DVI cables ($99 each :() in the mini display ports then plug the third monitor in to the DVI port on the card. You can use the regular DVI adapter if you only use two monitors.

I currently have two video cards driving my three monitors, but that doesn't seem to be an option on the 2010 Mac Pros, since I purchased the 5870. So, 2 of the Dual-Link DVI adapters are my only way to run three monitors. From the reviews on the Apple store, they may not work terribly well either.
 
drml said:
So, 2 of the Dual-Link DVI adapters are my only way to run three monitors. From the reviews on the Apple store, they may not work terribly well either.
Click to expand...

Well you can always get a cheaper video card than spending $200 on 2 adapters . . .
 
sboerup said:
Well you can always get a cheaper video card than spending $200 on 2 adapters . . .
Click to expand...

Can you? Is it possible to run another video card along side the 5870?

If so, which ones? I can't find reference of anyone running the 5870 plus another card (not surprising :)). The second card would have to be low power because all of the power plugs are used by the 5870.
 
Hmm I currently have 2x Geforce 120 in my MP, probably going to have my 5870 in slot 1 and the old Geforce 120's in the other slots. Being able to run 4 ACD =]. Won't know if it'll work till I get it but it's most likely it will.
 
drml said:
Can you? Is it possible to run another video card along side the 5870?

If so, which ones? I can't find reference of anyone running the 5870 plus another card (not surprising :)). The second card would have to be low power because all of the power plugs are used by the 5870.
Click to expand...

Well I''m currently running a 4870 and 2600xt in my 2008 MP . . . plan on keeping the 2600xt if needed, or just go to 2 monitors.
 
Fwiw, I also read that I would only need 1 Dual and 1 Single adapters for 3 DVI monitors. I tried every combination I could think of but no luck. After reading the above tech note I went down to my local Apple Store and got a 2nd Dual-Link adapter (and confirmed I could return it if it didn't fix the problem).

I now have all three monitors working. Maybe I don't need 2 Dual-Link adapters but I couldn't figure it out and that tech note seems to explicitly say you need two Dual-Link for 3 DVI monitors.

Good luck.
 
I've got an unusual problem with my 5870...

Sometimes on powering on, with my three monitors plugged-in (DVI + 2xMDP) it refuses to display anything on the screen - can only be solved by plugging in the DVI only and waiting for the grey screen and then plugging in the MDP's. It first occurred when I turned it on for the first time... for a total of two times (second time just now after starting up from freezing the machine). Main display runs on a MDP....

I'm not particularly sure what to make of it - since it doesn't seem to happen when I restart the machine of which I've done on numerous occasions from installing stuff...

hmmmm
 
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