There is a feature of Intel Core i series CPU--high frequency noise due to the energy-saving design. I don't know why they don't care about this high frequency noise when designed the system, but still some models seem to have no such problem. I guess maybe the manufactories need to use some more expensive soundproof components. Anyway, Sony obviously didn't notice this situation and let the noise problem become the main defect of all the core i CPU series.
Fortunately, Sony unlocks the BIOS setting of CPU support C3 C6 function. Now we can disable this energy-saving function to temporary make the noise disappear. But I think they still need to figure out some way to really solve the noise problem with c3 c6 function activation.
Due to the weak battery life, I bought a new BPS22 battery for my EA37. There is some tests for these 2 battery with c3 c6 activation or not.
First, the battery spec. is below:
- BPS22A: original supplied accessory of EA series--10.8V 5000mAh 6 cell
- BPS22: original supplied accessory of EB series--11V 3500mAh 4 cell