In order to get more bang for your buck, you really need to have a look at DB2 Symmetric Multiprocessing.
Written by Steve Pitcher
In the last couple of years, I've been turning on more POWER processor cores in order to compensate for an increased workload for our IBM i partitions. At the moment, I have 2.5 cores assigned to my primary partition and 0.5 cores assigned to a guest partition. Only a few years ago, we were using a fraction of a single POWER7 core's potential.