Bothersome MB alarm during render

Hey all. Having an annoyance wuth a frankenstein build. When I render a file my alarm beeps during the entire render. My temperatures look good and the cpu isn't over clocked. Where should I be looking to see what's triggering the alarm. The renders are short DNXHR 444 tests and come out fine.
MB:Asrock C602
2x E5-2670
2x 1050ti
4x 4TB 7200 drives
Windows 8.1 Pro

render a file my alarm beeps during the entire render.

Likely an overall brownout pulling down the computer's power supply. When Resolve commits to a render, all resources come on line, all drives spin. If you had an external UPS battery backup, it would be chirping, too. I often see draws that would trip the service breaker on a household mains supply.

jPo, CSI

That's probably it. I have a 1000w PSU. I'll replace it and test. The UPS was fine, but a 1200w may test that.
S

The alarm was my ups. I had plenty of power.