A modder by the name of Bandit5317 created this amazing mod of an original Xbox, cramming in a 320GB HDD (though no optical drive) in the process. It took six months to build, but looks absolutely amazing. The polycarbonate case holds the guts of a flashed Xbox, so even though it's got no DVD drive, it'll serve as a great media center with the help of XBMC. It definitely makes the current crop of consoles look bloated in comparison, though we're told it runs a bit hot due to the tight quarters inside. Still, it's a great mod, especially given the original Xbox's considerable girth. Source
That's damn impressive, there's got to be some board reduction done there somehow, the board in my xbox is the same as a mATX roughly.
That's pretty awesome. I doubt he did any board reduction, any parts you'd cut off would really render the board non functional, I don't think you could reconnect THAT many traces either. The xbox1 PSU was inside the case though, and I imagine he made it into an external power brick or a tiny proprietary ATX psu. This is very much the type of modding I really liked form the xbox1 days. Really ingenious design.