From searching this site, I also found this works if you don't want the IGPU enabled but want to use a system definition that does have IGPU.
Just add these boot arguments to config.plist:
Thanks Timbo for the information. I'll give it a try this weekend. The card works fine in Win7, which is what I bought it for. I'm using this card in my modded MacPro 2008 case because it is small and doesn't require a separate power supply. I can live with the current situation.
@Timbo 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. I wonder if you have seen this problem.
I’m using an HP K600 Quadro along with an ASUS P8Z77-M-PRO, 10.10.5...
I would suggest you use the Intel Power Gadget to monitor your CPU:
I'm using it to monitor my overclocked i7-2600k (4.3 GHz); works better than HWMonitor.