Hi,

>>
Maybe it is having a cooling problem, i.e. the fan is on the way out, they will slow down if they start to overheat.
>>
Throttling is enabled but the system shows 2.1GHz immediately on startup so don't think it's a cooling problem

>>Also is the power management disabled in the BIOS.
It is

>>Also is the CPU overclocked.
The processor model show 2.8GHZ so I assume not ?

Regards,
Viv