You're assuming that the game applies the same manner of stress as can be replicated in other applications, this is not correct.

This title is actually multithreaded (up to 4 cores) and puts more load onto the motherboard and cpu then many other recent AAA titles while also putting a heavy load onto the graphics card.

To replicate the same loading, you would need to do something like running Luxmark on the GPU and CPU at the same time, or another test that puts a great deal of loading on the memory and cpu, whilst the gpu is heavily in use.

Given you use a x58/1366 platform, have you checked that the IOH is not overheating?, this is actually common with x58 boards as many have pitiful cooling implementations for this chip, this chip can get up to 100c+ if the airflow or contact is bad. This particular chip does have a non-controllable OHP power-off implemented which is trigged around the 105c mark.

Similiarly, have you also made sure the ICH and IOH voltages are sufficient for the amount of usb or sata devices installed, you don't mention a mainboard, so i have to advise you that some vendors specified 1.05v which is below the intel spec of 1.1v(and even 1.1v is insufficient in a great deal of cases).