1. Recovery Speed and Reverse Recovery Time (trr): This is the fundamental difference. The GPP20J-E3/73 is a standard recovery diode (>500ns), while the 1N6628 is a fast recovery diode (trr=45ns). In switching circuits or high-frequency rectification, the 1N6628 exhibits significantly lower switching losses, noise, and heat generation compared to a standard recovery diode. Substituting a standard recovery diode for a fast recovery type in applications like switching power supplies or freewheeling circuits will lead to severe efficiency degradation, excessive temperature rise, and potential EMI issues. 2. Forward Voltage Drop (Vf): Under the same 2A test condition, the Vf of the 1N6628 (1.35V) is notably higher than that of the GPP20J-E3/73 (1.1V). The higher conduction loss of the 1N6628 results in greater heat generation during continuous operation, demanding more robust thermal management and contributing to lower system efficiency. 3. Rated Current and Design Margin: The GPP20J-E3/73 has a nominal current rating of 2A, slightly higher than the 1N6628's 1.75A. Combined with its lower Vf, this suggests the GPP20J-E3/73 may offer better steady-state current-handling capability and thermal performance. However, this advantage is limited to low-frequency operation due to its slower recovery speed. 4. Cost and Application Positioning: The 1N6628 commands a higher price, reflecting its fast recovery characteristics tailored for high-frequency, high-performance, or specialized fields (e.g., aerospace, military). The GPP20J-E3/73 is an economical standard rectifier diode intended for general-purpose applications like line-frequency rectification. This cost differential directly mirrors the performance gap and their distinct application scopes.