Radeon HD 6870 dual monitors

[szfxtrader]

Unfortunately, does not work for me. This machine isn't for me, it is for our studio, replacing an older mac pro. I don't think the monitors we have in the studio have HDMI (I don't work there, so I don't know). Plus, we'd eventually like to be able to have three monitors. two via DVI and one (TV) via HDMI.

There's quite a bit of stuff on this board about getting these to work.

I have an XFX6870 driving three 24" monitors at 1920x1200, GE=Y, QE/CI enabled.
1xDVI
1xHDMI (using an HDMI->DVI cable)
1xminiDP (using an active miniDP->DVI adapter. A passive adapter won't do the job)

I don't think anyone has got the second DVI to work.

Hi! Are you using SL or Lion? Could you please tell us(step by step) what you did to get the 3 monitors/desktops? Thanks in advance!

 

[straycat264]

Hi! Are you using SL or Lion? Could you please tell us(step by step) what you did to get the 3 monitors/desktops? Thanks in advance!

I had it working in 10.6.8, but I'm now on Lion.

There really isn't a step-by-step, as the card pretty much works OOB... there are just some things to be careful of, which caused me a degree of pain and wasted time, so I'll outline those:

1) GE=Y did not load the correct frame buffer until I installed UserDSDT. I'd previously used the EasyBeast option, and this plain didn't work for the card. When I downloaded the appropriate DSDT from this site, and installed using UserDSDT, it started working. Other people have said the same thing.

2) To connect two monitors, I can use 1xHDMI, and 1xDVI (or some miniDP combination). I can't use 2xDVI, as one of them plain doesn't work. To connect 3 monitors, I have to add in a miniDP. I used a miniDP -> DVI adapter for this, and the first adapter I tried was a passive one. Plugging it in blacked out one of the other monitors (I think it was the DVI, but I can't remember) - so I could still only have two monitors in use. Switching to an active adapter solved this problem. The adapter I use is the XFX branded on, purchased direct from XFX... but from what I can gather, any adapter which is labelled active should work. I've read a couple of reports that some of the Apple branded passive adapters work also, but I've no first-hand experience of this, and I wouldn't chance it myself.

3) My monitors are all 1920x1200. When hooking up via miniDP, I ended up with that one screen being corrupted / garbled after boot - I've seen this problem mentioned in a few places, and it only seems to happen at 1920x1200. Unplugging the monitor then plugging it back in, or changing the monitor resolution then changing it back fixed it, but that was something of a pain. Eventually, I solved the issue by setting the graphics mode to: 1920x1200x32 in my boot.plist. I have no idea whether this problem persists in Lion.

Hope this is of help.

 

[szfxtrader]

Hi! Are you using SL or Lion? Could you please tell us(step by step) what you did to get the 3 monitors/desktops? Thanks in advance!

I had it working in 10.6.8, but I'm now on Lion.

There really isn't a step-by-step, as the card pretty much works OOB... there are just some things to be careful of, which caused me a degree of pain and wasted time, so I'll outline those:

1) GE=Y did not load the correct frame buffer until I installed UserDSDT. I'd previously used the EasyBeast option, and this plain didn't work for the card. When I downloaded the appropriate DSDT from this site, and installed using UserDSDT, it started working. Other people have said the same thing.

2) To connect two monitors, I can use 1xHDMI, and 1xDVI (or some miniDP combination). I can't use 2xDVI, as one of them plain doesn't work. To connect 3 monitors, I have to add in a miniDP. I used a miniDP -> DVI adapter for this, and the first adapter I tried was a passive one. Plugging it in blacked out one of the other monitors (I think it was the DVI, but I can't remember) - so I could still only have two monitors in use. Switching to an active adapter solved this problem. The adapter I use is the XFX branded on, purchased direct from XFX... but from what I can gather, any adapter which is labelled active should work. I've read a couple of reports that some of the Apple branded passive adapters work also, but I've no first-hand experience of this, and I wouldn't chance it myself.

3) My monitors are all 1920x1200. When hooking up via miniDP, I ended up with that one screen being corrupted / garbled after boot - I've seen this problem mentioned in a few places, and it only seems to happen at 1920x1200. Unplugging the monitor then plugging it back in, or changing the monitor resolution then changing it back fixed it, but that was something of a pain. Eventually, I solved the issue by setting the graphics mode to: 1920x1200x32 in my boot.plist. I have no idea whether this problem persists in Lion.

Hope this is of help.

Thanks a lot! I am still fighting for 3 desktops on Lion.

 

[emooreart]

I'm on Snow Leopard 10.6.8 and have both dvi ports working. In multi beast under boot options I loaded the 64 bit GraphicsEnabler=No

On first reboot I got a kernal panic. second reboot was fine

Graphics - amd 6870
board - Gigabyte GA-Z68MX-UD2H-B3

 

[SoulWager]

As a temporary solution, try plugging the second monitor into the video card after you get to the login screen.

I'm currently using a Gigabyte GV-R6870C-1GD in 10.6.8, (default framebuffer).

I have an LCD on the dvi-d port, and an old CRT on the DVI-I(w/ adapter), and only the CRT will display anything until I unplug it and plug it back in.

Also, any idea why, whenever I try to force a framebuffer, it will throw a memory allocation error (ati.c line 739) or just ignore the specified framebuffer and load the default generic one instead?

 

[Hexa]

How are your benchmarks in Cinebench? I get around 34fps in MacOS and around 69 in Win64. :

Cinebench is reporting around 25fps.

Cinebench windows 76.58
1.PNG

Cinebench Lion 10.7.1 46.03

Cinebench Lion 10.7.2 48.76
3.png

How this is for you?

 

[pacemkr]

I'm using one HDMI, one DVI.

Just in case anybody gets different colors on the two screens. Check the Color tab in Display preferences. When I switched the other monitor to HDMI the "Display profile" switched on that one for some reason. I had to go in there and make sure that both screens had the same color profile.

 

[bigpoppyjoe]

I'm not sure about my boot plist, but neither of my DVI ports are picking up my second monitor. My HDMI works like a champ, but just getting nothing from either of my ports.

Halp?

 

[dchrissmith]

I'm on Snow Leopard 10.6.8 and have both dvi ports working. In multi beast under boot options I loaded the 64 bit GraphicsEnabler=No
Graphics - amd 6870
board - Gigabyte GA-Z68MX-UD2H-B3

So this actually worked for me too... but I really want 3 monitors and I've so far been unsuccessful. I can only get 2 monitors going period in any combination. These work:
1. (2) DVI's
2. (1) DVI (1) HDMI
3. (1) DVI (1) MiniDP to HDMI

But ultimately I want all 5 ports working!! Any thoughts?
Ideally I'd love to get (2) DVI's and (1) HDMI working.

 

[mexicanevo]

2nd DVI does not work at all, was able to get dual monitors to work one hooked to dvi and one hooked to a mini-dp (apple brand) to dvi connector!!!

Finally DVD player/Powerpoint no longer crash!!!

Thank you all for the help with this!