The SK Hynix Platinum P51 2TB is the objective winner of this comparison, securing more individual specification victories than its competitor. While the Samsung 990 Pro 4TB offers a significant advantage in storage space, the SK Hynix Platinum P51 2TB provides the most impactful performance gain, featuring a sequential read speed that is 97% better than the alternative. This makes the latter the superior choice for users prioritizing raw data access throughput over total drive volume.

Users who require maximum storage capacity for large libraries or extensive file collections should choose the Samsung 990 Pro 4TB, as it offers 100% more capacity than the alternative. Conversely, those who prioritize high-speed data retrieval and system responsiveness should opt for the SK Hynix Platinum P51 2TB. Selecting between these two drives depends entirely on whether your primary requirement is the ability to store more data or the ability to access that data faster.