Flawless Quad (Four) Monitors with PowerColor Radeon 6870

[brycv]

I just wanted to document this setup for anyone wanting four monitors on one video card. I ordered the PowerColor AX6870 1GBD5-2DH Radeon 6870 card.

http://www.amazon.com/PowerColor-DisplayPort-PCI-Express-AX6870-1GBD5-2DH/dp/B004BB1VL6/

This card has two Mini DisplayPort outputs, one dual-link DVI, one single-link DVI, and one HDMI. The HDMI and single-link DVI (I believe) are linked so you can only use four outputs at any one time. The key point to getting four monitors working is you MUST use Active Mini DisplayPort to DVI adapters. Even though there is an FAQ that says the Apple Mini DisplayPort to DVI adapters are active, mine are not.

I ordered two StarTech MDP2DVIS adapters that are listed as Active and work exactly as expected.

http://www.amazon.com/StarTech-com-MDP2DVIS-DisplayPort-Active-Adapter/dp/B004SUELLC/

Prior to having the Active Mini DisplayPort to DVI adapters, I was only ever able to get two monitors working regardless of what configuration I used (2 x MDP, 2 x DVI, 1 x MDP & 1 x DVI, 1 x MDP & 1 x HDMI, 1 x DVI & 1 HDMI). Any of those configurations seemed to work but plugging in a third monitor in any variety did not work.

I was able to get three monitors working with one Active adapter and one Passive adapter but did not test four at that time although I am fairly certain it would not work that way.

In any case, I am running three 1920x1080 monitors (two Acer H233Hbmid and one Samsung 2233SW) and one 2048x1152 monitor (Samsung 2343BWX), two from MDP2DVIS adapters, one from DVI, and one from HDMI. I just double checked that 2 x MDP & 2 x DVI worked and it did not. However, 2 x MDP & 1 x DVI (I think the dual-link) & 1 HDMI works perfectly.

All of this is running on a Gigabyte GA-Z68MX-UD2H-B3 motherboard with F9 BIOS with a Core i5 2405S processor (will be Core i7 2700K next week). I installed 10.7.2 using UniBeast and used the proper DSDT from the database. Everything works flawlessly and I am very happy with the setup.

 

[karacho]

 

[alux]

Great!!! thanks

 

[shibirian]

Very good to know! Especially about the active adapters.

 

[brycv]

Update on some Graphics Issues

I've been moving cables around and so forth and all of a sudden started to notice graphics glitches on startup. One of my monitors kind of pulses and is distorted until I unplug it from the 6870 and then plug it back in. This was only happening on the second monitor which is plugged into one of the MDP2DVIS adapters with a DVI-D cable.

I switched my cables around and made it so that my primary monitor was also connected to the first MDP2DVIS adapter with a DVI-D cable. All of a sudden, the same distortion on startup appeared there. However, the way it was plugged in before, MDP2DVIS to DVI/HDMI cable plugged into the HDMI port on my monitor, did not have any distortion problems. Also, my 2048x1152 monitor plugged into the dual link DVI port never has any distortion with a DVI-D to DVI-D cable.

I am going to keep testing to figure out what might be causing the issue. I have some adapters from DVI to HDMI that I will test as well to see if that has any effect on the issue. So, the bottom line so far is:

MDP2DVIS using DVI-D to DVI-D cable has distortion on startup
MDP2DVIS using DVI-D to HDMI cable has no distortion and works perfectly

I will keep working on this and post my results.

 

[brycv]

I've got everything working now including reboot with no issues such as distortion.

Like I mentioned in my last post, DVI to HDMI has no issues including on restart. I have tested four monitors in two different configurations now and I have both working exactly as they should.

My monitors show up in order as Mini DisplayPort 1, Mini DisplayPort 2, HDMI, and DVI (dual-link upper port in line with the rest of the ports). Plugging a DVI to DVI cable into the DVI port never has distortion. I have my Samsung 2343BWX 2048x1152 monitor plugged into it. The HDMI port has a Cables To Go DVI to HDMI cable plugged into it which goes to a Samsung 2233SW 1920x1080 display using DVI. These two monitors have not had distortion issues at all.

The primary and secondary display are plugged into MDP1 and MDP2 respectively. I have tested two Acer H233Hbmid displays and two Samsung 2233SW displays. I am using the two StarTech MDP2DVIS adapters like I mentioned before. If I plug DVI to DVI cables in and then plug them into either set of monitors I have distortion. If I use DVI to HDMI cables plugged into the HDMI ports of the Acer monitors there is no distortion. Also, if I used DVI to HDMI cables plus an HDMI to DVI adapter at the end to convert back to DVI, I also have no distortion. It's an odd workaround but seems to be fine.

To summarize (perfect meaning no distortion or any other issues):

• DVI dual-link port: DVI to DVI cable is perfect
• HDMI port: HDMI to DVI cable is perfect

• MDP ports: DVI to HDMI cable is perfect
OR
• MDP ports: DVI to HDMI cable to HDMI to DVI adapter is perfect

Thanks to all involved for all the great work so this can all work so seamlessly!

 

[brycv]

I use the same card!!
but on 10.6.8
I can't use the " Front Row"
when I open and Freeze the whole things...
have to Reset the power...

so can U post your setting?

my setting are
1.MultiBeast 3.10.1 with GraphicsEnabler=Yes

2. Use the netkas's 6870 package

but same!!!

BTW... I using 4 Screen ^_^

I have no idea about 10.6.8. I've never attempted using 10.6.8 with this system. Front Row is gone with 10.7 so I can't test that either. Sorry I can't be of more help.

I just used MultiBeast 4.2.1 with standard settings which is GraphicsEnabler=Yes. I used the DSDT for my board as well. I've actually moved to another board with my own custom generated DSDT (Intel DQ67EP) and it still works fine.

 

[rkarten]

Hi brycv,

Great findings and thanks for sharing!

I am looking for a 4 monitor setup myself and was wondering if you could confirm that this works with your graphic card. (zero adapters)

1. Apple cinema display 27" (2560 x 1440@60hz ) - mini displayport
2. Apple cinema display 27" (2560 x 1440@60hz ) - mini displayport
3. Additional lcd 24" (1920 x 1200@120hz) - dvi
4. Television 46" (1920 x 1080@60hz ) - hdmi

Since it is really hard to find this kind of setup, I really hope you could share your thoughts!

Thanks in advance.

 

[brycv]

Hi brycv,

Great findings and thanks for sharing!

I am looking for a 4 monitor setup myself and was wondering if you could confirm that this works with your graphic card. (zero adapters)

1. Apple cinema display 27" (2560 x 1440@60hz ) - mini displayport
2. Apple cinema display 27" (2560 x 1440@60hz ) - mini displayport
3. Additional lcd 24" (1920 x 1200@120hz) - dvi
4. Television 46" (1920 x 1080@60hz ) - hdmi

Since it is really hard to find this kind of setup, I really hope you could share your thoughts!

Thanks in advance.

Unfortunately I don't have any Apple Cinema Displays to test with at the moment. As long as they are the Apple Cinema Displays with Mini DisplayPort output and not the newest Thunderbolt version they should work. There may be some issues but they can be worked around. Do a search for Apple Cinema Display 24 or 27. I remember reading a thread about the cinema displays being off on boot but someone was able to work around the issue with a patch or something. I can't remember the details.

If you were to get the latest Thunderbolt ACD 27 models they would not work due to needing a Thunderbolt connection to work. That limits it to current Mac models except for the Mac Pro. Anyway, I hope that helps. If you do get the setup please report back on how it works out for you.

 

[rkarten]

Thanks a lot for your input!

I am going for the dp version, not the thunderbolt.

Probably the xfx instead of the powercolor for the card.

Once I get the displays, I`ll post my findings.