Monodisperse and semi-facetted ultra-small templated mesoporous silica nanoparticles (US-MSN) of 20-25 nm were synthesized using a short-time hydrolysis of tetraethoxysilane (TEOS) at room temperature followed by a dilution for nucleation quenching. According to dynamic light scattering (DLS), a two-step pH adjustment was necessary for growth termination and colloidal stabilization. The pore size was controlled by cetyltrimethylammonium bromide (CTAB) and the tiny amount of neutral surfactant F127 was added for minimizing the coalescence between US-MSN and favoring the transition towards internal ordering. Flocculation eventually occured allowing to harvest a powder by centrifugation ( 60% silica yield after one month). The scanning transmission electron microscopy (STEM) and 3D high-resolution transmission electron microscopy (3D-HR-TEM) images revealed that the US-MSNs are partially ordered. The 2D FT transmorm images evidences the coexistance of four, five and sixfold patterns characterizing an “on-the-edge” crystallization step between amorphous raspberry and hexagonal pore array morphologies, typical of a protocrystalline state. Calcination preserved this state and yields a powder characterized by a packing developping a hierarchical porosity centered at 3.9 ± 0.2 (internal pores) and 68 ± 7 nm (packing voids) of high potential as support for separation and catalysis.