My PC made a BEEP

[Alumno Superstes]

I don't know where to ask so I ask here if some wise sees this thread.

I just installed rtx 4080 Tuf OC and have tried witcher 3 runs good, but then opened cyberpunk, added all max (4k, v-synch 120hz, hdr RGB) except path tracing was off, when loaded save I heard BEEP.

Any clues what was it? All stable since then while writing this and tested earlier more after that BEEP, making ALL maxed, minus antialiasing..4k don't need it. Alos DLAA was off.

I have 850W psu (rog strix) 80 gold, I was thinking it fails, but should crashed by that time and smell would been burnt..none of those.

I use also UPS..would sudden use of electricity sapped it ..it should only work when electrics in house gets unstable...So another scenario would be that use of GPU made electctircs unstable so UPS waked up? I have lights on here did not see flickering on led lamps.

I would LOVE to know what the hell got me scared..more so if it repeats itself

PSU should be ok, 750W is recommended for this and I have 100w more,

EDIT: My 1st time was that I felt wrm breeze from PSU, so fan was running 1st time in it's lifetime..so something happened..usually fan rpm = 0 since it goes on high temps only

[Synopse]

https://www.pcmag.com/encyclopedia/term/beep-codes

[Alumno Superstes]

ok, thanx, those beeps are when pc boots up + my bios has 3-4 leds for errors, no speaker..

I came to conclusion it's my UPS, its 900VA (480W)..worked well with 1080 and 3060 ti, but seems some peaks goes over UPS's capacity now..if I understood manual right (good to keep those at safe place even if needed for once in lifetime) even if battery used only when AC goes jumpy, there is some kind warning at on-line.