HDMI has digital audio along with the digital video. DVI only has digital video. As far as picture quality goes I don't think HDMI will get a better picture than DVI, if that's what your thinking. And as mentioned the splitter will just mirror the one screen on both monitors. You won't be able to extend your screen across both monitors because they will both be connected to the one video card port. The splitter can't send different signals to each monitor. My monitors are all DVI input. My main monitor runs on a mini HDMI to HDMI cable that feeds a HDMI to DVI adapter. The other two monitors are connected to the two DVI ports on my video card. I don't use the sound portion of the HDMI anyway, I have speakers connected to my sound card.