BUILDING THE SYSTEM
As always the purpose of this section is not to build a functional system but rather to showcase what you can expect from the case at hand in terms of interior space.
It didn't come as a surprise to any of us so a full sized ATX mainboard takes up most available space.
Since you can only use CPU coolers up to 95mm in height your choices are limited to top down models like the AXP200 Muscle seen above (there's also room for the low profile fan but we misplaced our own).
With enough room for graphics cards up to 290mm in length (as long as the power ports are at the top) you should have no problem fitting almost any card in the market inside the RM1.
We went ahead and also installed a 3.5" HDD at the bottom of the RM1.
Final step (and an easy one at that) is the installation of a ATX PSU as seen above (i do recommend using a fully modular one however since you will need the least amount of cables inside such a small case).