Different readings on MacOSX vs Windows / BootCamp

[Crulex32]

I have considerably different CPU and GPU readings (with ~20 degree difference) on MacBook Pro (non-retina), 2012.
See reports taken on these OS within ~1 minute difference.
This difference keeps after few reboots back & forth.
When touching my MacBook Pro doesn't seem that hot, so Windows readings seem more realistic.
On MacOSX, this results in Fans running in full speed.

P.S. After few minutes of usage, readings on my Mac are down to normal again (76 / 75 C as on Windows).
Any clues?

MacOSX Yosemite:

Macs Fan Control 1.3.0
MacBookPro9,1
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz[105]
Mac OS X Unknown

Fans:
Left side-min{2000}curr{6201}max{6200}mode{0}
Right side-min{2000}curr{6199}max{6200}mode{0}


TempSensors:
TA0P (Ambient) - 48.5, 48.5
TB0T (Battery TS_MAX) - 34.6992, 34.6992
TB1T (Battery Point 1) - 34.6992, 34.6992
TB2T (Battery Point 2) - 33.7969, 33.7969
TC0E () - 101.969, 101.969
TC0F () - 102.766, 102.766
TC0P (CPU Proximity) - 74.625, 74.625
TC1C (CPU Core 1) - 97, 97
TC2C () - 95, 95
TC3C () - 102, 102
TC4C () - 96, 96
TCGC (PECI GPU) - 101, 101
TCSA () - 91, 91
TCXC () - 101.297, 101.297
TG0D (GPU Diode) - 77.625, 77.625
TG0P () - 66.125, 66.125
TG1D () - 81, 81
TG1F () - 81.3555, 81.3555
TG1d () - 75, 75
TGTC () - 0.125, 0.125
TGTD () - -1, 255.977
TM0P () - 45.25, 45.25
TM0S (DIMM Module 1) - 52.75, 52.75
TP0P () - 44, 44
TPCD () - 68, 68
Th1H () - 61.75, 61.75
Th2H () - 57.75, 57.75
Ts0P (Left Palm Rest) - 33.75, 33.75
Ts0S () - 49.2148, 49.2148
Ts1S () - 49.2148, 49.2148
Tsqf () - 78.8867, 78.8867


Disk drives:
Samsung SSD 840 EVO 500GB - 42
APPLE HDD HTS547575A9E384 - 36

Windows 7 x64:

Macs Fan Control 1.3.0
MacBookPro9,1
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz[105]
Windows 7 x64

Fans:
Left side-min{2000}curr{5912}max{6200}mode{0}
Right side-min{2000}curr{5913}max{6200}mode{0}


TempSensors:
TA0P (Ambient) - 47.5, 47.5
TB0T (Battery TS_MAX) - 34.7969, 34.7969
TB1T (Battery Point 1) - 34.7969, 34.7969
TB2T (Battery Point 2) - 34, 34
TC0E () - 91.3281, 91.3281
TC0F () - 92.668, 92.668
TC0P (CPU Proximity) - 67.75, 67.75
TC1C (CPU Core 1) - 77, 77
TC2C () - 75, 75
TC3C () - 82, 82
TC4C () - 76, 76
TCGC (PECI GPU) - 77, 77
TCSA () - 73, 73
TCXC () - 83.5625, 83.5625
TG0D (GPU Diode) - 68, 68
TG0P () - 63.75, 63.75
TG1D () - 72, 72
TG1F () - 77.7266, 77.7266
TG1d () - 66, 66
TGTC () - 0.125, 0.125
TGTD () - -1, 255.727
TM0P () - 45.625, 45.625
TM0S (DIMM Module 1) - 53.4766, 53.4766
TP0P () - 44.125, 44.125
TPCD () - 67, 67
Th1H () - 60.5, 60.5
Th2H () - 56.5, 56.5
Ts0P (Left Palm Rest) - 33.8125, 33.8125
Ts0S () - 48.6445, 48.6445
Ts1S () - 48.6445, 48.6445
Tsqf () - 76.9219, 76.9219


Disk drives:
Samsung SSD 840 EVO 500GB - 42
APPLE HDD HTS547575A9E384 - 36

[DreamSeason]

That's pretty hot in my opinion. Did you try to manually set the fan speed to a fixed value and then compare the temperature under both Windows and OS X without heavy load?

[Crulex32]

Hi, sorry for so long to reply... Missed any notifications about this post.

I've made 2 tests.
1) constant speed 2000 RPM, Windows & Mac;
2) constant speed 4000 RPM, Windows & Mac.

Results:

1) 2000 RPM, Windows:

Macs Fan Control 1.3.1
MacBookPro9,1
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz[105]
Windows 7 x64

Fans:
Left side-min{2000}curr{1995}max{6200}mode{1,2000}
Right side-min{2000}curr{2001}max{6200}mode{1,2000}


TempSensors:
TA0P (Ambient) - 50.125, 50.125
TB0T (Battery TS_MAX) - 35.5977, 35.5977
TB1T (Battery Point 1) - 35.5977, 35.5977
TB2T (Battery Point 2) - 33, 33
TC0E () - 86.7539, 86.7539
TC0F () - 87.6094, 87.6094
TC0P (CPU Proximity) - 68.5, 68.5
TC1C (CPU Core 1) - 83, 83
TC2C () - 81, 81
TC3C () - 84, 84
TC4C () - 83, 83
TCGC (PECI GPU) - 80, 80
TCSA () - 80, 80
TCXC () - 85.1719, 85.1719
TG0D (GPU Diode) - 73.875, 73.875
TG0P () - 67.125, 67.125
TG1D () - 77, 77
TG1F () - 78.5078, 78.5078
TG1d () - 71, 71
TGTC () - 0.125, 0.125
TGTD () - -1, 255.93
TM0P () - 45.25, 45.25
TM0S (DIMM Module 1) - 53.8633, 53.8633
TP0P () - 49.375, 49.375
TPCD () - 70, 70
Th1H () - 63.75, 63.75
Th2H () - 59, 59
Ts0P (Left Palm Rest) - 33.125, 33.125
Ts0S () - 49.4727, 49.4727
Ts1S () - 49.4727, 49.4727
Tsqf () - 44.7383, 44.7383


Disk drives:
Samsung SSD 840 EVO 500GB - 38
APPLE HDD HTS547575A9E384 - 33

2000 RPM, Mac:

Macs Fan Control 1.3.1
MacBookPro9,1
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz[105]
Mac OS X 10.10

Fans:
Left side-min{2000}curr{1998}max{6200}mode{1,2000}
Right side-min{2000}curr{2002}max{6200}mode{1,2000}


TempSensors:
TA0P (Ambient) - 52.5, 52.5
TB0T (Battery TS_MAX) - 35.6992, 35.6992
TB1T (Battery Point 1) - 35.6992, 35.6992
TB2T (Battery Point 2) - 33.2969, 33.2969
TC0E () - 104.109, 104.109
TC0F () - 105.539, 105.539
TC0P (CPU Proximity) - 78.75, 78.75
TC1C (CPU Core 1) - 103, 103
TC2C () - 103, 103
TC3C () - 104, 104
TC4C () - 101, 101
TCGC (PECI GPU) - 103, 103
TCSA () - 99, 99
TCXC () - 104.391, 104.391
TG0D (GPU Diode) - 90.25, 90.25
TG0P () - 76.25, 76.25
TG1D () - 94, 94
TG1F () - 90.9844, 90.9844
TG1d () - 88, 88
TGTC () - 0.121094, 0.121094
TGTD () - 0.105469, 0.105469
TM0P () - 46.625, 46.625
TM0S (DIMM Module 1) - 55.1406, 55.1406
TP0P () - 51.75, 51.75
TPCD () - 74, 74
Th1H () - 71.5, 71.5
Th2H () - 64.625, 64.625
Ts0P (Left Palm Rest) - 33.5625, 33.5625
Ts0S () - 52.1797, 52.1797
Ts1S () - 52.1797, 52.1797
Tsqf () - 44.7617, 44.7617


Disk drives:
Samsung SSD 840 EVO 500GB - 40
APPLE HDD HTS547575A9E384 - 33

2) 4000 RPM, Windows:

Macs Fan Control 1.3.1
MacBookPro9,1
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz[105]
Windows 7 x64

Fans:
Left side-min{2000}curr{4002}max{6200}mode{1,4000}
Right side-min{2000}curr{3999}max{6200}mode{1,4000}


TempSensors:
TA0P (Ambient) - 52, 52
TB0T (Battery TS_MAX) - 37.2969, 37.2969
TB1T (Battery Point 1) - 37.2969, 37.2969
TB2T (Battery Point 2) - 34.6992, 34.6992
TC0E () - 82.0156, 82.0156
TC0F () - 82.8477, 82.8477
TC0P (CPU Proximity) - 67.5, 67.5
TC1C (CPU Core 1) - 78, 78
TC2C () - 75, 75
TC3C () - 81, 81
TC4C () - 75, 75
TCGC (PECI GPU) - 75, 75
TCSA () - 72, 72
TCXC () - 80.5156, 80.5156
TG0D (GPU Diode) - 68.125, 68.125
TG0P () - 63.625, 63.625
TG1D () - 72, 72
TG1F () - 73.7969, 73.7969
TG1d () - 66, 66
TGTC () - 0.125, 0.125
TGTD () - 0.0117188, 0.0117188
TM0P () - 47.125, 47.125
TM0S (DIMM Module 1) - 56.1602, 56.1602
TP0P () - 48.625, 48.625
TPCD () - 70, 70
Th1H () - 60.375, 60.375
Th2H () - 56.75, 56.75
Ts0P (Left Palm Rest) - 34.3125, 34.3125
Ts0S () - 51.9336, 51.9336
Ts1S () - 51.9336, 51.9336
Tsqf () - 63.2305, 63.2305


Disk drives:
Samsung SSD 840 EVO 500GB - 42
APPLE HDD HTS547575A9E384 - 35

4000 RPM, Mac:

Macs Fan Control 1.3.1
MacBookPro9,1
Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz[105]
Mac OS X 10.10

Fans:
Left side-min{2000}curr{3997}max{6200}mode{1,4000}
Right side-min{2000}curr{4003}max{6200}mode{1,4000}


TempSensors:
TA0P (Ambient) - 50.375, 50.375
TB0T (Battery TS_MAX) - 38.5, 38.5
TB1T (Battery Point 1) - 38.5, 38.5
TB2T (Battery Point 2) - 36.2969, 36.2969
TC0E () - 95.5352, 95.5352
TC0F () - 98.8516, 98.8516
TC0P (CPU Proximity) - 74.5, 74.5
TC1C (CPU Core 1) - 97, 97
TC2C () - 95, 95
TC3C () - 99, 99
TC4C () - 94, 94
TCGC (PECI GPU) - 97, 97
TCSA () - 90, 90
TCXC () - 97.6094, 97.6094
TG0D (GPU Diode) - 79.125, 79.125
TG0P () - 67.375, 67.375
TG1D () - 83, 83
TG1F () - 81.3398, 81.3398
TG1d () - 77, 77
TGTC () - 0.125, 0.125
TGTD () - 0.078125, 0.078125
TM0P () - 46.5, 46.5
TM0S (DIMM Module 1) - 54.5938, 54.5938
TP0P () - 47.75, 47.75
TPCD () - 71, 71
Th1H () - 63, 63
Th2H () - 58.5, 58.5
Ts0P (Left Palm Rest) - 35.5625, 35.5625
Ts0S () - 51.2344, 51.2344
Ts1S () - 51.2344, 51.2344
Tsqf () - 63.2383, 63.2383


Disk drives:
APPLE HDD HTS547575A9E384 - 36
Samsung SSD 840 EVO 500GB - 42