The Samsung 990 Pro 4TB is the objective winner of this comparison, securing victory across five of the seven evaluated specifications. Its most significant advantage is its storage capacity, which is 300% greater than that of the alternative. By offering substantially more room for data, this drive provides a clear lead in overall utility for users who require extensive space for their files and applications compared to the Silicon Power UD90 1TB.

The Samsung 990 Pro 4TB is the superior choice for power users and professionals who prioritize maximum storage capacity for their systems. Conversely, the Silicon Power UD90 1TB is the better option for budget-conscious buyers, as it holds an 87% advantage in MSRP. Selecting between these two components depends entirely on whether your primary requirement is the expansive storage volume offered by the former or the cost-efficiency provided by the latter.