I have a Gigabyte GA-P55-usb3 board with an nVidia 240 vid card (PCI 16x 2.0). I use this as my work PC as a software developer. I currently have 2 displays running on it and would like to add a third. This will require adding a second video card.
I'm a little confused about whether I can add a second card to the PCIe 4x slot and, if so, what kind. Most cards seem to be PCI 16x 2.0. Will it fall back to the 4x? The board's manual is very vague as to the slot specs and there is no information on adding video cards. I know that the board does not do SLI.
Does anyone have experience with this board (or the GA-P55A-UD3 which is very similar) with a second graphics card?
My only requirement is that the second card be able to support 1920x1050 resolution.
In searching for an answer, I found this article on PCI bandwidth utilization. It seems to suggest that a video card that normally requires 16x will scale down to the number of lanes actually available. If I am understanding this correctly, this should mean that I can use a 16x card in a 4x slot but with less performance. I'm not really concerned about speed in this case since this display will not be used for gaming.
I guess the only other thing to determine is whether a 16x 2.0 card will work in the 4x slots of these particular boards. The manual doesn't indicate whether the 4x slot is 2.0 or 1.0. Or does that not matter?