Lets do something else. Post again the above values with 0% cpu utilization (idle, nothing runs) and 100%.
with boinc set to use 100% cpu on 3 cpus the 4th is always reserved for cuda and my desktop. cuda is set for 0.35cpus
sensors
coretemp-isa-0000      
Adapter: ISA adapter
Core 0:      +55.0°C  (high = +84.0°C, crit = +100.0°C)
coretemp-isa-0001
Adapter: ISA adapter
Core 1:      +50.0°C  (high = +84.0°C, crit = +100.0°C)
coretemp-isa-0002
Adapter: ISA adapter
Core 2:      +50.0°C  (high = +84.0°C, crit = +100.0°C)
coretemp-isa-0003
Adapter: ISA adapter
Core 3:      +50.0°C  (high = +84.0°C, crit = +100.0°C)
it8718-isa-0290
Adapter: ISA adapter
in0:         +1.22 V  (min =  +0.00 V, max =  +4.08 V)
in1:         +1.89 V  (min =  +0.00 V, max =  +4.08 V)
in2:         +3.22 V  (min =  +0.00 V, max =  +4.08 V)
in3:         +2.94 V  (min =  +0.00 V, max =  +4.08 V)
in4:         +1.87 V  (min =  +0.00 V, max =  +4.08 V)
in5:         +0.08 V  (min =  +0.00 V, max =  +4.08 V)
in6:         +1.04 V  (min =  +0.00 V, max =  +4.08 V)
in7:         +2.96 V  (min =  +0.00 V, max =  +4.08 V)
in8:         +3.30 V
fan1:       2288 RPM  (min =    0 RPM)
fan2:       2115 RPM  (min =    0 RPM)
fan3:       1406 RPM  (min =    0 RPM)
fan4:       1415 RPM  (min =    0 RPM)
temp1:       +39.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermistor
temp2:       +43.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermal diode
temp3:        -2.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermistor
cpu0_vid:   +1.219 V
with boinc shut down and time given for everything to cool off average cpu usage is 0 to 1% peaking at 5% momentarily
sensors
coretemp-isa-0000      
Adapter: ISA adapter
Core 0:      +40.0°C  (high = +84.0°C, crit = +100.0°C)
coretemp-isa-0001
Adapter: ISA adapter
Core 1:      +39.0°C  (high = +84.0°C, crit = +100.0°C)
coretemp-isa-0002
Adapter: ISA adapter
Core 2:      +38.0°C  (high = +84.0°C, crit = +100.0°C)
coretemp-isa-0003
Adapter: ISA adapter
Core 3:      +38.0°C  (high = +84.0°C, crit = +100.0°C)
it8718-isa-0290
Adapter: ISA adapter
in0:         +1.23 V  (min =  +0.00 V, max =  +4.08 V)
in1:         +1.89 V  (min =  +0.00 V, max =  +4.08 V)
in2:         +3.23 V  (min =  +0.00 V, max =  +4.08 V)
in3:         +2.96 V  (min =  +0.00 V, max =  +4.08 V)
in4:         +0.69 V  (min =  +0.00 V, max =  +4.08 V)
in5:         +0.08 V  (min =  +0.00 V, max =  +4.08 V)
in6:         +0.42 V  (min =  +0.00 V, max =  +4.08 V)
in7:         +2.98 V  (min =  +0.00 V, max =  +4.08 V)
in8:         +3.30 V
fan1:       1917 RPM  (min =    0 RPM)
fan2:       2115 RPM  (min =    0 RPM)
fan3:       1406 RPM  (min =    0 RPM)
fan4:       1415 RPM  (min =    0 RPM)
temp1:       +38.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermistor
temp2:       +33.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermal diode
temp3:        -2.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermistor
cpu0_vid:   +1.219 V