DonkeyOatie :
OK, those symptoms could still be thermal (or not) but they suggest cooer issues rather than CPU issues. To track this down, we are going to need a systematic approach and a lot of data. HWMonitor can tell you most of what we need to know at the moment. We need to know the processor speed, voltages, usage, and temperature when it runs fast, and we need to know how this changes, and in what order, when it slows down.
I'm assuming you have no big background tasks that kick in and start doing something when you are gaming and that you are not getting important parts of your work from an internet connection that might slow down.
I just double checked, and it slows down even if I leave it alone doing nothing, without even starting a game, yet restarting immediately fixes the problem, for about the same amount of time every time.
I'll try to post what information I thought was relevant, but I'm not too savvy on all of this. I could post the whole thing of each one here, or wherever if it'd be more convenient. Just not sure the best way to go about sharing the data.
I noticed the Voltage 7 on the CPU VCORE is higher after the restart. Could it be a power supply issue or something? Just random guessing at this point, since I honestly have no idea anymore.
After restart:
Hardware monitor Nuvoton NCT6792
Voltage 2 3.39 Volts [0xD4] (AVCC)
Voltage 3 3.39 Volts [0xD4] (3VCC)
Voltage 7 1.04 Volts [0x82] (CPU VCORE)
Voltage 8 1.79 Volts [0x70] (VCCIN)
Voltage 9 1.50 Volts [0x5E] (DRAM)
Voltage 10 11.26 Volts [0x80] (+12V)
Voltage 11 5.16 Volts [0x81] (+5V)
Temperature 0 35°C (95°F) [0x23] (SYSTIN)
Temperature 3 41°C (105°F) [0x29] (TMPIN3)
Fan 1 2156 RPM [0x86C] (CPUFANIN)
Fan 3 1036 RPM [0x40C] (AUXFANIN1)
Hardware monitor ACPI
Temperature 0 28°C (82°F) [0xBC2] (TZ00)
Temperature 1 30°C (85°F) [0xBD6] (TZ01)
Hardware monitor Intel I/O
Clock Speed 0 399.91 MHz [0x18F] (Graphics)
Hardware monitor NVIDIA NVAPI
Voltage 0 0.98 Volts [0x3CF] (VIN0)
Power 0 8.00 pc (GPU)
Temperature 0 40°C (104°F) [0x28] (TMPIN0)
Fan 0 1410 RPM [0x582] (FANIN0)
Fan PWM 0 42 pc [0x2A] (FANPWMIN0)
Clock Speed 0 135.00 MHz [0x87] (Graphics)
Clock Speed 1 324.00 MHz [0x87] (Memory)
Temperature 0 42°C (107°F) [0x3A] (Core #0)
Temperature 1 42°C (107°F) [0x3A] (Package)
Power 0 31.98 W (Package)
Power 1 24.78 W (IA Cores)
Power 2 0.00 W (GT)
Power 3 7.20 W (Uncore)
Power 4 2.48 W (DRAM)
Voltage 0 1.04 Volts (VID)
Voltage 1 +0.00 Volts (IA Offset)
Voltage 2 +0.00 Volts (GT Offset)
Voltage 3 +0.00 Volts (LLC/Ring Offset)
Voltage 4 +0.00 Volts (System Agent Offset)
Slow idle:
Hardware monitor Nuvoton NCT6792
Voltage 2 3.36 Volts [0xD2] (AVCC)
Voltage 3 3.38 Volts [0xD3] (3VCC)
Voltage 7 0.72 Volts [0x5A] (CPU VCORE)
Voltage 8 1.79 Volts [0x70] (VCCIN)
Voltage 9 1.50 Volts [0x5E] (DRAM)
Voltage 10 11.18 Volts [0x7F] (+12V)
Voltage 11 5.12 Volts [0x80] (+5V)
Temperature 0 36°C (96°F) [0x24] (SYSTIN)
Temperature 3 42°C (107°F) [0x2A] (TMPIN3)
Fan 1 2160 RPM [0x870] (CPUFANIN)
Fan 3 999 RPM [0x3E7] (AUXFANIN1)
Hardware monitor ACPI
Temperature 0 28°C (82°F) [0xBC2] (TZ00)
Temperature 1 30°C (85°F) [0xBD6] (TZ01)
Hardware monitor Intel I/O
Clock Speed 0 600.07 MHz [0x258] (Graphics)
Hardware monitor NVIDIA NVAPI
Voltage 0 0.98 Volts [0x3CF] (VIN0)
Power 0 58.61 pc (GPU)
Temperature 0 59°C (138°F) [0x3B] (TMPIN0)
Fan 0 1770 RPM [0x6EA] (FANIN0)
Fan PWM 0 53 pc [0x35] (FANPWMIN0)
Clock Speed 0 1201.94 MHz [0x4B1] (Graphics)
Clock Speed 1 3004.68 MHz [0x4B1] (Memory)
Temperature 0 34°C (93°F) [0x42] (Core #0)
Temperature 1 38°C (100°F) [0x3E] (Package)
Power 0 24.12 W (Package)
Power 1 16.57 W (IA Cores)
Power 2 0.00 W (GT)
Power 3 7.54 W (Uncore)
Power 4 2.39 W (DRAM)
Voltage 0 1.04 Volts (VID)
Voltage 1 +0.00 Volts (IA Offset)
Voltage 2 +0.00 Volts (GT Offset)
Voltage 3 +0.00 Volts (LLC/Ring Offset)
Voltage 4 +0.00 Volts (System Agent Offset)
Slow in game:
Hardware monitor Nuvoton NCT6792
Voltage 2 3.36 Volts [0xD2] (AVCC)
Voltage 3 3.38 Volts [0xD3] (3VCC)
Voltage 7 0.76 Volts [0x5F] (CPU VCORE)
Voltage 8 1.79 Volts [0x70] (VCCIN)
Voltage 9 1.50 Volts [0x5E] (DRAM)
Voltage 10 11.18 Volts [0x7F] (+12V)
Voltage 11 5.12 Volts [0x80] (+5V)
Temperature 0 35°C (95°F) [0x23] (SYSTIN)
Temperature 3 39°C (102°F) [0x27] (TMPIN3)
Fan 1 2160 RPM [0x870] (CPUFANIN)
Fan 3 996 RPM [0x3E4] (AUXFANIN1)
Hardware monitor ACPI
Temperature 0 28°C (82°F) [0xBC2] (TZ00)
Temperature 1 30°C (85°F) [0xBD6] (TZ01)
Hardware monitor Intel I/O
Clock Speed 0 599.86 MHz [0x257] (Graphics)
Hardware monitor NVIDIA NVAPI
Voltage 0 0.98 Volts [0x3CF] (VIN0)
Power 0 61.32 pc (GPU)
Temperature 0 61°C (141°F) [0x3D] (TMPIN0)
Fan 0 1740 RPM [0x6CC] (FANIN0)
Fan PWM 0 53 pc [0x35] (FANPWMIN0)
Clock Speed 0 1201.94 MHz [0x4B1] (Graphics)
Clock Speed 1 3004.68 MHz [0x4B1] (Memory)
Temperature 0 35°C (95°F) [0x41] (Core #0)
Temperature 1 40°C (104°F) [0x3C] (Package)
Power 0 29.02 W (Package)
Power 1 21.52 W (IA Cores)
Power 2 0.01 W (GT)
Power 3 7.50 W (Uncore)
Power 4 2.49 W (DRAM)
Voltage 0 1.04 Volts (VID)
Voltage 1 +0.00 Volts (IA Offset)
Voltage 2 +0.00 Volts (GT Offset)
Voltage 3 +0.00 Volts (LLC/Ring Offset)
Voltage 4 +0.00 Volts (System Agent Offset)