Do you have a rear case fan fitted? If not, fit one (if you have space). Use the largest your case will accomodate. This will help in drawing warm/hot air out of the system before it reaches your PSU, which will help it run cooler and quieter (since you won't need to use the turbo mode). If your temperature monitoring is for the PSU, I would be concerned at temperatures of that level - is the PSU providing sufficient wattage (amperage) on each voltage line? If your old unit overheated, this could possibly indicate that your system was trying to draw more power from it than it could supply, with the result that its internal components were being overheated. You state that the new PSU is a 500W model. What was the rating of the old one? I might have gone for a 600-650W model instead as that would have more power reserve.