Im currently using a DVI to DVI connetion for my HD monitor
A friend told me i should also connect a DVI-HDMI into the same exact monitor so i have both th DVI to dvi and the dvi to hdmi into the same monitor.. does this benefit the monitor in any way?
More aboutplug graphics card montior twice
Not at all. Your monitor has 2 different inputs. They are only used one at a time unless you have a Picture in Picture option of some sort.
I would suggest not listening to your friend for any more technical advice
There is usually a setting in the monitors menu to select whichever port you have the video connected to, at least on the monitors I have seen. Some may be "auto-detecting" as well. But basically, yeah, the monitor can only use one port or the other, not both at the same time.