Usually, Intel motherboards have a option that allow you to change the maximum turbo boots setting if its available on BIOS, but we do not recommend this process since it will overloaded the processor and could damage it.
Please note that Intel® Turbo boost is engaged automatically depending on processor’s load, voltage, power and temperature. Therefore, at a particular moment the processor may reach 3.3 Ghz or 3.7 GHz depending on those variables.
thanks for replying Sylvia, my MSI Z77A-G45 Thunderbolt mobo does have that option to change the max turbo (multiplier) of my Xeon to 37x, it even has the 'Enhance Turbo' option to apply max turbo to all cores. But the max I get is always 35x to all 4 cores. Someone at a certain forum told me that this Xeon doesn't have the limited overclok (+4 from the max turbo) like some main stream processor (e.g i7-3820). But other said that through certain board like ASUS or ASRock can apply max turbo through an option that's called 'Multi Core Enhancement' (MCE). Is there anyone here has the mobo with the MCE feature and has similar processor to the one that I have ?
I would suggest pointing to the nature of the Intel® Turbo Boost technology. This feature is auto-managed by the processor having a balance between the power consumption and the chip heat.
Also, the maximum Turbo Boost speed won’t be reached by all of the processor cores at the same time, the value is assigned to the cores being used gradually at the moment the Turbo Boost kicks out so it is possible that only one core reaches the maximum Turbo Boost speed assigned by default.
If you change the Turbo Boost frequency multiplier manually then the processor will try to apply it to the cores in use but if the maximum power allowed (TDP) is already covered then the CPU won’t continue increasing the cores speed to prevent heat problems. Since you are setting a new value manually for the Turbo Boost frequency multiplier it is possible that the CPU is finding a power limit when reaching the 3.5GHz.
If you compare this Xeon processor (max TDP 69W) with the I7-3820 (max TDP 130W), the behavior will be different because the architecture is not the same. The Intel I7 processor is able to get to the maximum turbo frequency since it has higher TDP.
Again, you can change the settings, but we do not recommend.