PC make some noise when rendering heavy project AE.

Hello,
When rendering heavy project (about 2000 or more light layers) in 2560x1440 PNG sequence in AECS6 (no multiple frames), PC makes some slightly hearable noise (like vertical sync noise) with 3 seconds interval. PC is cold, i mean CPU and GPU temps are pretty standart about 48-50 degrees. I am sure the project isn’t too heavy (not extreme for PC).
i7 4790K 4GHz, Gigabyte GTX970, 16GB ram.

When rending less heavy projects - everything is fine. Maybe some know an easy answer.
Thanks.

Most likely it is noisy (whistling, squeaking, crackling, etc.) SMT power inductors on the video card. This device, with a large inductance, filter variable component after the DC power converters. Increasing load current and grows. I’m on the GTX770 graphics card had a similar problem too.

http://www.futureelectronics.com/en/inductors/power-inductors.aspx

Thanks. How do you think is it critical for graphic card or not very serious overload?

It is difficult to say because it depends on the electronic components of the card. Self noise is not a malfunction. It’s just says it does not use the most expensive components. But in any case, leaving the computer for a long render, card, processor and memory should be well cool.