For our temperature tests we loaded the system for 15 minutes using Prime 95 and recorded the CPU temperature using CPUID HWMonitor. We then restarted the system and left it idling at the desktop for 15 minutes before recording temperatures. Room temperature was maintained at 18 degrees Celsius for the duration of the tests.
We can see that the performance differences between the coolers become more pronounced when the system is overclocked. The Corsair H100i has a clear lead over the original H100 by 3 degrees C in performance mode.