Hi, I have a cMP with a GT120. I know the GT120 does not support 4K but I'd assume it should negotiate a lower resolution. When I connect it to a 4K monitor (Dell P2415Q) using the DisplayPort output I never see the boot screen. At some point a small progress bar appears on the lower left of the screen and then I get the login screen. When I connect it using the DVI output (using a DVI->HDMI cable, because the monitor only has DisplayPort and HDMI inputs) I can see the boot screen, but up to a point, then the screen is black. Anyway, that's for the GT120 and my current issues. I'm researching for a new card, but it is not easy to know if the boot screen will show up. There are threads saying that you need to be in 30Hz mode, others saying that only specific cards do that, etc. It appears that not all graphics cards can properly negotiate a working resolution when connected to a 4K screen during boot up, even if flashed. Is that correct? Is that an OSX bug? I would have thought they could start up in 1080p for example, and then switch to 4K, but it does not seems the case, right? Alternatively, which cards are supposed to show the boot screen at 4K over DisplayPort? Any advice will be highly appreciated.