Are you running both experiements on the same computer? With the exact same code?
Does your real world data has some weird properties (like almost zero)?
Sorry, this code belongs to our lab and is not allowed to be distributed without permission.
What causes the difference in forward time between the test and the real world task in general?
Well I can’t think of anything really
It may be some discrepancy in your timing scripts?
It may be external factors?
It may be that they don’t actually have the same size?
It may be that your net does different things depending on the values (like a rnn where the length is controlled by the network itself)?