Armm

I put Arctic Silver 5 on the Ultra Bay and replaced the thermal pads with some from an xbox 360, had to thin them out first, and my temps are peaking at about 83-85 under load from the ultrabay gpu. I just had my mother board replaced less than a month ago so it has fresh thermal paste on it. On board CPU and GPU usually floats around 80 degrees. Was thinking of doing the bios mod. Is this reversible if I backup my original bios image? I also have it on cooling pad with the bottom removed as well as the idea fan script. I have about 3 months left on my warranty. Trying to avoid voiding it out until I have to with my luck.