No, the oscilloscope’s memory depth selection has an automatic mode. In this mode, the oscilloscope will ensure that the sampling rate is sufficient and try to select the minimum memory depth

Memory depth is a concept that only digital oscilloscopes have. This parameter does not exist in analog oscilloscopes. The signal entering the digital oscilloscope passes through the front-end amplifier, then the analog-to-digital converter, and the collected signal is stored in the memory through the trigger system. Finally, the data is processed and displayed on the screen. In this process, the capacity of the memory is the physical medium that represents the size of the digital oscilloscope’s memory depth.
Memory depth (memory depth) is also called record length (record depth). The general index is written as 28Mpts, which means there are 28 million sampling points (pts=points). The memory depth, sampling rate, and waveform recording time satisfy the following formula: sampling rate = memory depth ÷ waveform recording time.