NVidia and ATI Mobo compatibilities

Well, I have been working on building my first PC from the ground up, and have pretty much everything ready to go except the video card. I do not remember where I read this, but I saw something about nVidia cards not working well with an AMD motherboard. I have been trying to investigate this, even went to nVidia's website last night to see if they had any compatibility charts for each video card they produce, but I was not so lucky.

To get to the just of this post, I am trying to check the credibility of that claim. Is it true that nVidia cards have troubles on an AMD motherboard? Is it something that has to do with each motherboard manufacturer, ie. a gigabyte board does not have a problem, but an MSI board does.

So maybe this might help, I will just jot down what I am throwing together...

CPU - AMD Phenom II X2 550 Black Edition Callisto 3.1GHz

MoBo - GIGABYTE GA-MA770T-UD3P AM3 AMD 770 ATX AMD

and since that mobo does not have an onboard video card, I went with a cheap Raedon for now until I can get to the bottom of this...

GPU - SAPPHIRE 100225L Radeon HD 3870 512MB 256-bit GDDR4


So my overall question would be asking if I can use an nVidia card on that mobo, such as a 9800 GTX or even a 200 series. I am sorry if a post has been made like this before, I am still trying to figure out the search features for the TH Forums. I will try to work on that in the future though! Any answers a much appreciated, thank you  .