Computer shuts down while playing games. Could this be for the PSU?

[KumarjitDey]

While playing the newest games like Watch Dogs, Thief, and even Sniper Elite 3, the computer is either shutting down or rebooting itself after some time (this could be after 1 minute or even after 30 minutes!).

My specs are:

8gb RAM
Sapphire AMD HD 7870 HDMI OC Edition 2 GB GDDR5 Graphics Card
AMD FX 8-core Processor
970A-G46 Mobo
550 W (Cooler Master) PSU

My graphics card is fine. It has been repaired a month ago (yes, it WAS causing problems). I'm sure it isn't causing anymore trouble now.

Could anyone please tell me what could be the problem? Thank you in advance.

 

[Josh McGiff]

Do you have windows 8/ did you build the pc from scratch with parts that were bought from a shop not re-used

 

[DoctorHoliday]

According to Steam, your computer specs are more than enough for those games, so it shouldn't be a problem with your parts. However, you never stated whether or not you have any DVD drives, lights, or extra fans as that could be using up more power from your PSU. Also you might want to check your CPU and GPU temps under load; computers sometimes shut down to prevent any damage to the components when they get too hot. Run a stress test like OCCT or Prime95 and check the temps.

 

[KumarjitDey]

Do you have windows 8/ did you build the pc from scratch with parts that were bought from a shop not re-used

Win7 64-bit

Yes, its a 1 year-old assembled PC. And no, I'm not re-using any parts.