Motherboard MSI Z68A-G43/G3 (MS-7750) 
CPU Type QuadCore Intel Core i5-2550K 
NVIDIA GeForce GTX 670. 
The value of the CPU temperature is initially high (52 C) 
 
But after the GPU stress test for 5 minutes, grows to very large values ​​(120 C). 
 
CPU stress test does not affect this figure. 
The other indicators are not a concern. 
What do you think about this situation?