I have no info on this so I'm trying to find you an answer.

Just wanted to follow up, still waiting on confirmation from the product management team. Hopefully should have an answer soon.
 
Thank you for your patience. 

Thanks for checking.  I suppose that means that there is no 4K(60hz) support in OSX for Displayport MST either.

rjohnson11

Ownie
Thanks for checking.  I suppose that means that there is no 4K(60hz) support in OSX for Displayport MST either.

I would say that your assumption is most probably correct.

Trying to get some information on this port as well, most likely same limitations. Once I find i'll definitely post back here. 

Ownie
OSX Mavericks must support 4K in some form or another since the new Mac Pro claims to have the functionality.    In anycase, I'd be much obliged if you'd tweek this fine card to have an HDMI 2 port that supports (60hz) 4K GPU for Mac Pro3,1 Early 2008.   I think 4K HDMI 2 UltraHDTVs are on the horizon.   Either that or create an adapter for this card that will allow for 60hz 4K to HDMI 2.

The Display port is going to be limited to the same resolution, 2560x1600. I don't believe, at this time, there is going to be any modifications to the Mac Edition 680. If you have any other questions feel free to let us know. 

Joey:
 
Would you be good enough to test this card with a 4K display using the display port connector? It has been established that OSX Mavericks has full support for 4k resolution in the software, so we just need to know if there is driver level support for 4k from your Mac card. I doubt the specs will answer this; you have to just test it by connecting the card in a 2010 Mac pro to a 4K display via display port and see if the right resolution shows up on the monitor. The fact that the Quadro K5000 works at 4k in OSX suggests that this card should work as it is based on the same Nvidia chipset.
 
I will buy this card in an instant if you can confirm this works (at 60Hz).

Can anybody confirm that 4k monitors work at 60Hz over the DisplayPort? Just got the GTX 680 Mac Edition and it would be great with a 4k monitor (but not at 30Hz).
 
It would be great to use an IPS monitor like ASUS PB279Q and prices are not quite reasonable but I like to know it works before buying...
 
btw, I'm using OSX 10.10.

I have a Dell UP2715K monitor. It's a 5K monitor (requires two DisplayPort 1.2 cables) but I'm using it as a 4K monitor for now (using one DisplayPort 1.2 cable). SwitchResX says the dot clock is 533.25 MHz at 4K. I can't tell that the monitor is supposed to do 5K while I'm using it at 4K. You would have to use a particular test pattern to see any issue. I'm using Mac OS X 10.11.5 and a GTX 680 Mac Edition in a 2008 Mac Pro. I also have a Skylake Hackintosh with a EVGA GeForce GTX Titan X SC Gaming. I might replace that with a 1000 series card when they make one that has at least 12 GB like the Titan X.
 
I've tried 5K on the Titan X in 10.11.4. There was a minor issue enabling it (have to power off and on the display after startup) so it's not super usable yet in Mac OS X (it can cause kernel panics). The 680 doesn't have dual DisplayPort so it can't do 5K. 5K works perfectly in Windows 10. The 5K features make the Dell UP2715K slow to wake from sleep (5 seconds?) even while doing 4K.
 

cMP 1,3 - do you mean MacPro3,1?
 
I have a MacPro3,1 (Mac Pro 2008) running macOS 12.6.2 Monterey using OCLP. HDMI audio works. Maybe OCLP will work with 10.13.6 or 10.15.7. It's easy to switch between booting with and without OCLP by holding the option key at boot time to get into the Apple Startup Manager. I have all macOS versions installed on my MacPro3,1 from 10.4 to 13.1 and use OCLP for Big Sur and later. I have OCLP set to spoof MacPro7,1 but I think the default is not to spoof which might be preferable for you if you want to use it to boot earlier macOS versions.
 
Instead of OCLP, maybe try the HDMIAudio.kext. Check macrumors, insanelymac, or tonymacx86. There's a version 1.1 which I have installed for Catalina. I have 1.0 installed for Mavericks, Sierra, El Capitan, Yosemite, High Sierra - I guess I didn't get around to updating those to 1.1. I haven't tested any of them recently.