1. Performance Specifications: The 166B variant features significantly superior clock frequency (166 MHz) and access time (3.5 ns) compared to the 100B model (100 MHz, 5 ns). This is not merely a difference in isolated parameters but reflects the core speed grade designation. The higher data throughput bandwidth and lower read/write latency of the 166B model provide greater system performance headroom in demanding real-time processing or high-bandwidth applications. 2. Timing Margin: When using the 166B model in the same system design, its faster access time yields increased timing margin for data setup and hold. This enhances system stability under voltage and temperature variations, or alternatively, allows for the use of more relaxed (lower-cost) controller timing constraints. 3. Power and Signal Integrity Considerations: Theoretically, the higher-speed version may exhibit slightly higher dynamic power consumption. More critically, operation at the increased frequency imposes stricter requirements on PCB signal integrity design (e.g., clock, address/data trace routing). When substituting the part, it is essential to verify that the existing PCB layout and routing can support stable operation at 166 MHz to avoid timing violations or signal ringing issues.