I have the same motherboard as well and my CPUs get up to 60C with an unmodified sdr file and two 4U Supermicro heatsinks. My case has (3) 120mm PWM fans and (2) 80mm fans in the rear, so I can only speak for my setup and it's temps.Well, that certainly wasn't my experience. I'm using an Intel chassis with two 120mm fans and the Intel tower heatsinks. It has full control of the fans via PWM. The fans stay at idle until the CPUs got to about 80C. Then they ramp as far as necessary to maintain that temperature. Based on what I saw the only way it would hit lower temps under full load is by my messing with the acoustic profile and altitude setting in the BIOS which increases the minimum PWM value / idle fan speed. That would have to be done to the point where even under full load it can't hit generate enough heat to the thermal target and the fans never speed up.
I changed the .SDR file around and lowered the thermal target to about 60C. The fans spin pretty slow at idle and it doesn't get crazy hot under load.