a simpler word for instances are parellel units
if somebody is trying to understand through a pipeline diagram,
@Arjun sir I think the above diagram is wrong bcz we are calculating G3 and G4 using two instances of UG, after that, we are calculating G5 and G6 but where we are storing the result of G3 and G4. Also nowhere told that extra buffers are there.
I think this can be the correct diagram.
@samarpita Correct. As it is not mentioned when is $F$ reading the value of $G(X_i)$ and there are no mention of extra buffers.
In fact we need a lot of buffers practically.
Your diagram seems correct.
Just assume we have two stages in pipeline. They are G & F taking 3 & 5 seconds.
We have two instances of Uf & Ug. It is like having dual core processor. We have two pipeline processors.
So we will do i=1 to 5 in one processor & i= 6 to 10 in another processor.
So they will be done in parallel.
So only focus on i=1 to 5.
In ideal pipeline processor CPI=1 (First instruction takes full time, after it in every cycle one instruction gets completed unless there is any form of hazard)
So from 5 instructions, first one will take (5+3)= 8ns
For the rest 4 instructions in every 5 ns, 1 instruction will be completed. (Since max(5,3)=5)
So total time taken = 28 ns (ans)
This might also work .