Figure 3-11 shows the measured CPU times, general CP (bar in bold) and zIIP (bar that uses  the pattern) for different combinations of processors for SMT-1 and SMT-2 scenarios that use  the same workload. For configurations that used 1 - 4 zIIPs, the CP CPU time (which is chargeable) is less when  SMT-2 is enabled for the zIIP engines. After all zIIP eligible processing is offloaded for SMT-1,  no difference in CP CPU time between SMT-1 and SMT-2 was observed, as expected.  Figure 3-11 SMT-1 and SMT-2 CPU times comparison Chapter 3. Synergy with the IBM Z platform  103