One vs multiple servers - problem Consider the following problem:
We have a simple queueing system with $\lambda%$ - probabilistic intensity of queries per some predefined time interval.
Now, we can arrange the system as a single high-end server ($M/M/1$, which can handle the queries with the intensity of $2\mu$) or as two low-end servers ($M/M/2$, each server working with intensity of $\mu$).
So, the question is - which variant is better in terms of overall performance?
I suspect that it's the first one, but, unfortunately, my knowledge of queuing / probability theory isn't enough.
Thank you.

If "overall performance" is the expected time a client/customer/query spend in the M/M system, then the single server system outperforms the second one.
The reasoning is simple: the M/M/1 system functions in "full" intensity even with a single query at the system; the M/M/2 system needs two queries present to reach the highest service intensity. 
So, queries arriving at an empty system spend less time on the M/M/1. [Queries arriving at a system with at least one query present spend them same time on average]
