I have recently upgraded my moms computer with a Xeon L5420 which replaced a E7200 one. I did not change the cooler which is the stock one because I thought it would handle the low voltage L5420 one easily but no. All 4 core temperatures are somewhere near 70 degrees and the CPU temperature is only 35 degrees, I put enough termal paste. What is the problem? Should I buy a new cooler? What is the problem?