5770 and GTX 680 in Mac Pro - Games in Windows?

I'm running a GTX 680 for Windows gaming in my machine. The card is capable of 4 displays but in OS X due to Nvidia drivers or OS X itself it is limited to 2. More than 2 and it crashes on startup. With this in mind and the fact that I would still like a working boot screen I decided to keep one of my 5770's. I run both in my Mac Pro.

How do I run my games in Windows using the GTX 680? Do I need to disable the 5770 via device manager or if the GTX 680 is the primary card will it be 'first choice'? Will the GTX 680 suffer if it runs along side the 5770 in windows?

I appreciate any experience.

cosmicjoke said:

You need to plug the displays you intend to game on into your gtx 680...

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I kinda figured that out Will games by default be using the GTX 680? Does it have to be the primary card? Does the 5770 have to be disabled?

Asgorath said:

Wait, are you saying the 680 only supports 2 displays under OS X? Which OS and driver are you using? Try running "ioreg" from the Terminal and look for lines like this:

| | | +-o PXS2@0 <class IOPCIDevice, id 0x1000001c0, registered, matched, active, busy 0 (185 ms), retain 23>
| | | | +-o NVDA,Display-A@0 <class IONDRVDevice, id 0x1000003b0, registered, matched, active, busy 0 (116 ms), retain 8>
| | | | +-o NVDA,Display-B@1 <class IONDRVDevice, id 0x1000003b1, registered, matched, active, busy 0 (0 ms), retain 8>
| | | | +-o NVDA,Display-C@2 <class IONDRVDevice, id 0x1000003b2, registered, matched, active, busy 0 (0 ms), retain 8>
| | | | +-o NVDA,Display-D@3 <class IONDRVDevice, id 0x1000003b3, registered, matched, active, busy 0 (0 ms), retain 8>

Pretty sure that indicates my card supports 4 displays, as expected. FWIW I'm running 10.8.2 with the latest NVIDIA driver.

Click to expand...

All that indicates is the hardware the card has, it doesn't mean that the drivers will function correctly with more than 2 displays.

cosmicjoke said:

Nope, you just need to be playing the game on a display plugged into the gtx 680... you can set up a primary monitor as one of the ones plugged into the gtx 680 in display preferences if you want the game to default launch to that display... also you can play windowed mode and just drag the game to one of the displays plugged into the gtx 680.. really the only noteworthy thing is that the game won't be accelerated by the gtx 680 on the displays plugged into the 5770...

Click to expand...

Cheers, no performance impact?

You definitely remember correctly, I also remember reading about it before I bought the card. I have solved this problem.

Turns out since I was running one DVI and one HDMI the second DVI slot couldn't be DVI-VGA. I purchased a straight through DVI single link cable and presto 3 monitors. Windows was fine with the DVI to VGA on one DVI port and one DVI to HDMI on the second DVI but OS X was not, it's a driver issue in OS X that hopefully 10.8.3 has fixed.

To anyone reading this and wondering if it is fixable, good news it is as simple as ensuring the two monitors on the DVI ports are DVI-D cables, you can use DVI-D to HDMI or whatever you like but it has to be DVI-D.

The mistake I made was running one DVI port at DVI-D and one at DVI-I.

Two DVI-D is required if using both the DVI ports in OS X, at least with the latest drivers available in OS X and from Nvidia.

Really simple mistake to make and hopefully this helps someone. Thank you for everyones input.