I bought a Antec 900 case and a new heatsink (zerotherm nirvana 120mm) to go along with my AMD 64 FX-62. I'm using coretemp and speedfan to record my temp settings. My cpu right now is running at 53c, and i know it should be way cooler with they heatsink i installed. I went on Arctic silver 5's website and applied the same thermal paste to the specifications they have with my cpu, but the temp still want lower. I have tried to raise/lower the fan speeds, but nothing works. I'm really running out of options. I have researched the web for 2 hrs to find nothing that can help me out. Any suggestions woud be very helpful. Thanks.
Your CPU package has 2 "cores" inside. Each core has a temp sensor. Overall "CPU" temps may come from averaging these or from a third temp sensor somewhere. Definitely not from the heat sink!
However, the "core" temps are most useful as that temp info comes from the parts of the CPU that you are actually worried about. Depending on the CPU, different temp programs may or may not be properly calibrated. Please post the varous core temp readings you get along with which program gives which readings.
For example, I would trust Coretemp more than speedfan.