Actually if your system is reporting high temperature under high workload, you will need to check for motherboard manufacturer. All temperature reporting is down to the motherboard mainly.
It can be due to any of these:
a) bad integration
b) PSU not ATXv2.2
c) Chassis is not TAC (Thermally Advantage Chassis)
d) BIOS Issues.
e) Monitoring Software
Make sure that you are reading the temperature from the BIOS itself.
Possibly, in your case, if the temperature in the BIOS is stable, there is nothing wrong with the system. The monitoring software can report wrong information sometimes.
Since you are using a non-Intel Board, i cannot advise you to use Intel Monitoring Software, it wont work. Intel software are designed to work on intel board and the reporting result can be checked from our datasheet for further information.
What OS? What software do you use to measure the temp.? Try another software. If you do not have problems, my advice is to not upgrade BIOS, a faulty temp. readout is normal , find an IR temp. measurement tool ( thermometer ) or just use a multimeter with the temperature measurement attachment ( thermal couple i guess in English ) and measure directly the temperature of the CPU, the core temp. is not reported correctly in many cases, and even it is, it's always higher than the CPU temp, as it's taken inside the CPU and the CPU temp. mainly by sensors in the MB, but not always and not on all cpu/mb so... Just make a burn test and see if it fails that is the best thing to do and be sure that your system is stable.
If the reporting temperature in the BIOS is 30c, then definitely there is nothing wrong with the CPU and the board. Probably, the software is misreporting the temperature as Setekh said in the previous post.
I dont know if Gigabyte does have their own monitoring software, if yes, it is best to use it, as it is designed to work with the board Gigabyte.
Like Intel has Intel Desktop Utilities.
All the best,