GTX 680 second screen blank/black?

[stringsibanez]

Hi,

I recently swapped an EVGA GTX 680 into my system as both an upgrade from a Quadro FX 380 (which was pretty underwhelming) and because it was a lot easier than continuing to fight with the problematic 270x I had initially tried.

Anyway, the core part of the system is:

HP Z800 Workstation
Dual Xeon x5670 6-core processors @2.93GHz
48GB ECC Registered DDR3 1333 RAM installed (12 x 4GB sticks)
EVGA GTX 680 (DVI-I, DVI-D, HDMI, & Disaply Port available as outputs)
OS X 10.8.5

I run a pair of Samsung S24D590 LED displays in order to work efficiently, however, with this new graphics card I am only able to get a picture on one of the two displays.

a) My left-hand (primary) display is connected via the DVI-I port on the card -> DVI-to-VGA adapter -> 15' VGA cable -> VGA port on the monitor and works just fine.

b) My second display I have attempted to connect via the card's HDMI port (and the DVI-D port -> DVI-to-HDMI adapter) -> HDMI cable -> HDMI port on the monitor (I have tried both ports on the monitor), but the display just shows a blank/black screen.
Note: The display seems to correctly identify that there is a signal or something on the given HDMI port as it will stop cycling sources on the connected HDMI port. I have also tried any combination of "Display Settings" within OS X 10.8.5 without any change.


Any suggestions would be much appreciated.
Thanks,
-strings

 

[Fl0r!an]

Disable Inject / Nvidia in your config.plist (or GraphicsEnabler in case you're still on Chameleon / Chimera).

 

[stringsibanez]

Thanks for the response.

I do have GraphicsEnabler=No in Chameleon's boot config.. is there another flag?

 

[Fl0r!an]

No, that's the one I was talking about. Does OS X correctly detect the full amount of VRAM on your card?

 

[stringsibanez]

No, that's the one I was talking about. Does OS X correctly detect the full amount of VRAM on your card?

Yes, with this card OS X is correctly recognizing all of the card's VRAM as well as it's other specs and the revision number.. Definitely playing nicer with 10.8.5 than the 270x I had been trying.

That said, is it possible that this could be due to the HDMI cable possibly being a v1.3 instead of 1.4 (the cable doesn't say)? It is/was the only one I had that is long enough to make the run from my machine closet to the desk where I work, but I'm wondering if it might be worth picking up another cable just to rule that out?

 

[Fl0r!an]

Yes, could also be a bad cable...