You got a PWM CPU-fan? Maybe the fan RPM just goes up when stressing the CPU more, which can cause the temp. to drop. When your CPU is idle the fanspeed is low = a little more heat.
CPU: Intel 3570k with Corsair H60 watercooler @4.1ghz
GPU: Nvidia Asus GTX780 @1140/6600
PSU: Corsair 750W
RAM: Corsair 8gig DDR3-1600
MOBO: Asrock Z68m ITX
HDD: 500gb SSD EVO
CASE: Lian-Li PC-Q08 mini-ITX case
OS: Windows 7 x64
I use a fully configured emulator frontend (Maximus Arcade) to play every console & arcade game instantly
GPU: Nvidia Asus GTX780 @1140/6600
PSU: Corsair 750W
RAM: Corsair 8gig DDR3-1600
MOBO: Asrock Z68m ITX
HDD: 500gb SSD EVO
CASE: Lian-Li PC-Q08 mini-ITX case
OS: Windows 7 x64
I use a fully configured emulator frontend (Maximus Arcade) to play every console & arcade game instantly