CES 2016 - Origin PC just stepped it up a couple of notches with their very own SFF chassis they're calling Chronos. This follows in the footsteps of their other unique full and mid-tower cases that they debuted last year.
The new one Chronos SFF chassis is tiny yet spacious, able to support the necessary cooling power needed for an overclocked i7-5960X with a closed-loop liquid cooler. And though it's miniscule, it has up to three expansion slots to fit a Titan Z, should you be so inclined.
So if you're in the market for a custom-built SFF system, this 11.75x4x13.75" monster can be yours in Q1 of this year.