no I don't use a second monitorIf you already have the dual link cable and your graphics card and monitor both support dual link DVI, then I don't see any reason to have to switch to HDMI unless you are using multiple monitors and the correct monitor is not being identified as the primary monitor when you boot, in which case you might want to switch to HDMI as that will take precedence over DVI in the display preference.
no I don't use a second monitor
thank you for your helpThen there is little reason to worry about having to use HDMI. It's not going to "give" you anything you can't get from dual link DVI except audio.
I have another question. should I plug my headphone in back io, front cabinet io, or monitor? I'll get a asus b360 mobo which has supremefx audio chipset on moboFor sure. No problem.
thank you so much againBack or front I/O shouldn't matter so long as the front I/O is connected to the same type of audio header on the board that the back I/O uses. If it's a much older case or board that uses AC97 audio in front rather than HD audio, then use the back. If it's connected to an HD audio header on the board, then it doesn't really matter which of them you use but I tend to prefer to use the back I/O if it's not a real problem in terms of accessibility since it's direct to the motherboard with no additional cabling or hardware to potentially present any issues with sound quality.