— classic, but not the most optimal option for the location of the PSU. First, heated air from system components can accumulate in the upper part of the case; this negatively affects the cooling efficiency. However, for desktops, as well as large "towers" (see "Form factor"), this moment is not particularly relevant, and in general it becomes noticeable mainly with high performance (and heat dissipation) of the system. The second point concerns "towers" of small height — in them, the PSU located on top can block part of the motherboard and prevent the installation of a powerful cooler. However, this point is highly dependent on the layout of a particular case.
