Well, good thinking is sometimes the only thing that works with Apple. 
Anyway, I´ve read that if you switch in Vista/7 the system performance to high - don´t ask me where and how it´s called, sth in the energy management afaik - the system will utilize Turbo Boost even when it does idle around, so I guess it does force the CPU to and with 4C Turbo of the XEON it´s kinda nice to have.
However, 80+°C aren´t good IMO because it´s also near the throttle down mark of these CPUs and if they throttle down the system will react really choppy.
Anyway, I´ve read that if you switch in Vista/7 the system performance to high - don´t ask me where and how it´s called, sth in the energy management afaik - the system will utilize Turbo Boost even when it does idle around, so I guess it does force the CPU to and with 4C Turbo of the XEON it´s kinda nice to have.
However, 80+°C aren´t good IMO because it´s also near the throttle down mark of these CPUs and if they throttle down the system will react really choppy.