Tests of IBM Lotus Domino 8 performance show that upgrading to Lotus Domino 8 and the new Lotus Notes 8 client should yield positive results. Tests show CPU reductions across the board as well as I/O reductions on most platforms when compared to Lotus Notes and Domino 7. Read more about the test results...

Source: http://www.ibm.com/developerworks/lotus/library/domino8-server-perf/