Computer-aided simulation performed via two independent methods (the Monte Carlo method and method of dissipative particle dynamics) is performed for studying the effect of microphase separation in concentrated solutions of diblock copolymers composed of linear blocks A and amphiphilic blocks A-graft-B. The type of microstructures generated by strong incompatibility between units A and B is shown to be controlled by the ratio of block lengths. For example, in the case of short amphiphilic blocks, elongated micelles with correlated mutual alignment are formed. In the case of longer amphiphilic blocks, lamellar structures are produced; with an increase in the length of this block, these structures are transformed into sequences of lamellas containing parallel layers, lamellas with intersecting layers, and perforated lamellas. When the system contains long amphiphilic blocks, bicontinuous structures arise.