This is a default fans' response to CPU heavy load. How many fans do you have installed? Inspect the heat sink and if damaged, replace. Depending on your system configuration and with fully populated of hard drives, PCIe devices etc; you may need additional cooling by introducing additional fans. Apply this current iDRAC with LifeCycle Controller update: [URL] 
Hi, I have PowerEdge server T620 with Two cpu E5-2670. Bot of them temperature is near 70 С. (Idle is 70 and under full load max 76) Is this normal temperature for that CPU with 056JY6 heatsink?
T620 CPU temperature