It seems like your PC (a laptop, I guess
) is suffering overheating.
If you use entropy (equo, sulfur) to install/update things, it is normal that the process eats up a lot of CPU power. If your CPU fan isn't clean then u will have overheating problems and your PC will automatically shutdown/reboot when it reaches a critical temperature.
That's why the CPU fan is noisy with high CPU usage
I recommend a cleanup for your CPU fan. U will need to dismember your PC by parts, so be careful... or bring it to a tech service for a full cleanup.
Finally, if your CPU is a 64bit one, use a 64bit version of sabayon. (i recommend, is not mandatory
I hope it helps
Sabayon Linux Fully updated
CPU: AMD FX 4100 @4515MHz
RAM: 8GB Corsair Vengeance LP DDR3-1600
Video: Ati Radeon HD7770 - 1095MHz core 1GB GDDR5 @1250MHz
Lenovo ideapad S205 - 11.6" HD screen - AMD E450 APU - Ati HD 6320 - 4GB DDR3 RAM