This discussion will be interesting only for those who have added to the goal the minimalism of a powerful PC.
I've been silent for too long. But now, when Intel firmly pushes tiny NUC while ignoring prospective potential of Mini ITX form factor, I'm anxious to share my thoughts of what Mini ITX system could be IF...
I think there are people who want to move to Mini ITX form factor, but they can't. They are unable to install the GPU card AND the second card they NEED. This is my trouble too. So the idea of Mini ITX improvement is to put SECOND PCIE slot (speed x1) for the second component user would like to install (to me it's advanced sound card) into Mini ITX platform. I think it is possible:
I would like to know the demand for additional PCIEx1 on Mini ITX motherboards. Please, leave your opinion here.
Some thoughts to the case composition: the CPU cooler should be used of this type with the exhaust right to the side of the case. With such cooler the PCIEx1 card would be low profile though. Best placing of the standard PSU is like in this Silverstone SG09. So it will be powerful ultra compact enthusiastic PC with dimensions like 270x350x170 mm. I didn't any sketching to determine actual size because it's useless, I've just left these thoughts here and it feels easier now.
I build Intel based systems into old Nintendo Entertainment System cases. Ive built them with i3s and a 6670 low profile vid card inside, building one now with a G530 and a 7750. Can pack a lot of power into a small form factor.
Oops! I just realized Mini-DTX is close to what I'm talking about. But still I think Mini ITX with two PCIE slots is possible and it would be smallest case for performance that Micro ATX platform has (with single GPU card).
Sorry guys! Seems I didn't manage to express my thoughts in a clear way. First post has been rewritten now.