Performance evaluation is often carried out through simulations. You need to ask questions such as (a) What are some performance metrics for comparison - e.g. speedup, bandwidth, throughput, power, etc. (b) how can these be measured? (c) When actual prototyping is not possible, one has to use simulations - how do I model the architecture for simulation and defend the model? (d) Sometimes, queuing theory may be useful.

I hope this helps.