I've been thinking a lot about SFF problems and everytime i end up with the same idea:
For me, that live in a tropical country, cooling and properly dissipating the heat generated by a GPU is the first and biggest concern in a SFF case project. With that in mind, i started to do the reverse enginering of most ITX motherboard's design: the PCI-e area is almost always clear (and obviously should be, since GPU compatibility depends on it a lot!).
So i started to think about a case that is made to house all the computer component's, except for the GPU. That is advantageous in several ways:
1) thermal headroom: most of the GPU heat will spread to the external enviroment and wouldn't need any active cooling to be manageable;
2) overall volume reduction: if the case is meant to be used without PCI-e extender/riser, the GPU dictates case's height. on the other hand, if the GPU is housed externaly, the height of the case is bound to CPU heatsink and memory heights, that tends to be way smaller than expansion cards.
3) easy clean-up and overall maintenance: need to clean GPU heatsink? no problem! need to upgrade/replace GPU? no problem?
And here are my inicial thoughts for such a case:
* interchangeable (or adjustable) PCI-e bracket - or whatever name that piece that holds the back of GPU - capable of accommodating low profile and standard GPUs, as well as dual and single slot versions too;
* HTPC style. the smaller the height, the better;
* dual layer storage. SSDs and slim HDDs accommodated underneath mobo;
* one-piece-ish case. two pieces of cut'n'bended metal conected together by a couple of hinges;
I guess that's all. Please, feel free to criticize and give your feedback on the idea.
oh, and i'm trully sorry for the bad english too. this text was writen in a hurry and english is not my first language!