Correct.
In general dive computers sample ambient data (pressure, temperature) and run decompression algorithm (and in most cases the ascent algorithm too) every second.
You could think of this as the "algorithms clock". This is not user programmable.
The rate at which a dive computer stores data in a log is usually way different (slower) that the algorithm clock and it is called "sampling interval". Basically what the sampling interval does is to decimate the data to reduce its size so more logs can be stored in the internal (limited) memory.
