I was trying to solve a question dealing with n instructions in an uneven pipeline with k stages. I came across a generic formula for even pipelines i.e. (k + n - 1) * clock cycle. But I feel this should not work for uneven pipelines as the above formula is based on fact that the 1st instruction takes time = sum(time of k stages) and the 2nd instruction onwards takes time = maximum of stage delays.
A example: A pipeline is designed with 5 stages having execution times respectively as 3ns, 4ns, 2ns and 4ns. How much time will it take to execute 1000 instructions?