This will send a standard 1080p signal to your projector, but applications (the desktop etc) will only render to a letterboxed 1920x817 portion of the display.
Bandwidth doesn't matter when it comes to digital displays - what matters is what the device will accept and sync to.
My TV accepts anything up to 1080p60 - but it will only accept 1080p24/50/60 (plus or minus 3% or so) rather than any value in the range of 24-60Hz.
I doubt you will find many devices that will sync to 72Hz properly, or accept anything that is not a standard HDMI resolution. (720p/1080p for HD signals)Edited by Chronoptimist - 5/1/13 at 4:40am