Have you had this happen to you and if so, did you come up with a solution? If I boot with only the DisplayPort on and then attach the DVI after it's booted, all is well. The problem that I have is that when both monitors are on at boot, the DVI monitor is the primary monitor and the DisplayPort monitor constantly flickers on and off. This command in terminal ( ioreg -l | grep IODisplayEDID) also shows that my two monitors are recognized by the graphics card. This command in terminal (kextstat | grep -i nv) shows that the Nvidia drivers are being used, even though the Nvidia Driver manager app in the menu bar shows that I’m using the default OS X graphics Driver. I’m using an HP K600 Quadro along with an ASUS P8Z77-M-PRO, 10.10.5, Clover 3241 (nvda_drv=1 Inject Nvidia), Nvidia WebDriver-346.02.03f01, two Dell Monitors, one connected via DisplayPort the other with DVI. If anyone needs specific arguments/ist info for getting this mobo up and running with the Yosemite installer, drop me a I have a similar setup and am using two monitors, but I have a problem with one of them constantly flickering on and off and unusable if I boot with both attached and on. Heck, who am I kidding I'll likely test all the graphics cards I have back to the 8400GS (or whatever the heck it is). An SSD helps for this sort of troubleshooting as you don't have long to wait also really nice is Clover's ability to create the basic (but possibly buggy) DSDT and SSDT files on the fly, etc… So far, I've seen no evidence that anyone has reported full success with this on 10.10.5…hopefully I'll be able to do full bench testing with the card tomorrow (or later in the week pretty exhausted from the effort to get this working the past two days! If that doesn't work, I'll to an old 8800 card and the HD4000 iGPU. Also the restarting twice thing in the middle of the install is also…disconcerting to say the least.) Anyhoo, I'll let you all know if I get full graphics capabilities on the Quadro 600. (The hard part was realizing that I needed to bootstrap things a little more complex then the basic Clover UEFI install tutorial, etc, etc. I'm going to experiment further with this as I just managed to get this system installed completely. I also turned down the PCIE from v 3 to v2 on the main board slot but am not certain that this was the issue or not. To get this to work at all, I had to disable the IG on my MSI Z77A-G41 board. I just finished a clover install of Yosemite 10.10.5 with my Quadro 600 card. Okay, this appears to be booting in Yosemite 10.10.5 using the Aug 17 release build of Clover. Building a CustoMac Hackintosh: Buyer's Guide

Nvidia quadro k600 driver update