1. Recovery Speed & Type The RGP10D is a fast recovery diode (trr=150ns), whereas the 1N3611 is a standard recovery type (trr>500ns). In applications like switching power supplies, freewheeling, and high-frequency rectification, the RGP10D offers lower switching losses, reduced noise, and superior reverse recovery characteristics. Using the 1N3611 in such circuits may lead to significant heating, reduced efficiency, or voltage spikes. 2. Forward Voltage Drop (Vf) The 1N3611 has a lower Vf (1.1V) compared to the RGP10D (1.3V), indicating slightly lower steady-state conduction losses. However, this advantage is typically negated by its slower recovery speed. In switching applications, the dynamic losses from slow recovery far outweigh the minor difference in Vf. 3. Reverse Recovery Charge (Not Explicitly Stated) & Capacitance The RGP10D provides a clear junction capacitance specification (15pF @4V). As a fast recovery diode, its reverse recovery charge (Qrr) is generally low. The 1N3611 datasheet lacks this data, but standard recovery diodes typically exhibit higher Qrr, which leads to higher switching transient currents and increased EMI risk. Summary: Although both diodes share identical steady-state voltage/current ratings, their dynamic characteristics are fundamentally different. Directly replacing an RGP10D with a 1N3611 in a switching circuit originally designed for the former (e.g., high-frequency rectification, freewheeling, snubber, PWM output) is likely to cause reliability issues. Substitution may only be considered in applications insensitive to recovery time, such as line-frequency rectification or low-speed signal processing, but thermal performance and actual operating conditions must still be verified.