Does cutting the power to a busy PC damage it?

[PolishGod]

An electrician stupidly cut the power to my room without warning me so I didn’t put the PC in sleepmode or anything (maybe I should’ve just put it in sleepmode but I’d expect a professional to not get the room wrong), the pc was using 100% of the gpu and like 25% ram and cpu, the data seemed to be autosaved so my life might not be over, it is interpolating super mario bros the movie to 240 fps so it’s using ai to generate images and outputting them to a lot of short scenes

 13900k, 64 gb ddr5 and the gpu not kidding gtx 1070, 1 kW titanium

So the power was cut to the pc as it was doing all that and I wanna know if doing it just once can damage the PC (tiny declines in performance count as damage) or if data-loss is really all you have to worry.

[Needfuldoer]

It's probably fine. Power loss can cause data corruption to files that were actively being written to at that moment, or were in an SSD's DRAM cache and hadn't been flushed to NAND yet. (Many SSDs have a capacitor inside that keeps just enough power in reserve to flush the cache in the event of power loss.)

 

But causing physical damage? What you do think happens when you click "Shut Down" and your power supply cuts power off?  The horror stories you hear about power outages damaging computers are usually rooted in the surge that happens when power suddenly comes back, or a "brownout" condition where voltage or frequency is far below spec.

[KaiAurora]

Not really, the only damage you have to worry about is a power surge when the power comes back on but most PSUs have protection against that, although it is recommended to use a surge protector too.

 

In terms of data loss its more rare these days as a lot of clever things are happening to prevent it at hardware and OS level. Some SSDs include capacitors which will flush the cache during a power loss to prevent any data lost in that cache for example.

 

 

[Agall]

11 minutes ago, PolishGod said:

An electrician stupidly cut the power to my room without warning me so I didn’t put the PC in sleepmode or anything (maybe I should’ve just put it in sleepmode but I’d expect a professional to not get the room wrong), the pc was using 100% of the gpu and like 25% ram and cpu, the data seemed to be autosaved so my life might not be over, it is interpolating super mario bros the movie to 240 fps so it’s using ai to generate images and outputting them to a lot of short scenes

 13900k, 64 gb ddr5 and the gpu not kidding gtx 1070, 1 kW titanium

So the power was cut to the pc as it was doing all that and I wanna know if doing it just once can damage the PC (tiny declines in performance count as damage) or if data-loss is really all you have to worry.

Probably not, I've had to flip the power switch on the PSU possibly thousands of times at this point, including high power machines and servers.

 

Either way, you should have your system on a UPS. A 10ms loss of power is far less of a problem than a >10ms loss of power to a PC, even if that >10ms loss of power isn't really a problem.

[PolishGod]

1 hour ago, Needfuldoer said:

It's probably fine. Power loss can cause data corruption to files that were actively being written to at that moment, or were in an SSD's DRAM cache and hadn't been flushed to NAND yet. (Many SSDs have a capacitor inside that keeps just enough power in reserve to flush the cache in the event of power loss.)

 

But causing physical damage? What you do think happens when you click "Shut Down" and your power supply cuts power off?  The horror stories you hear about power outages damaging computers are usually rooted in the surge that happens when power suddenly comes back, or a "brownout" condition where voltage or frequency is far below spec.

Uhh I'm pretty sure clicking shut down shuts down all programs and then the components properly unlike a powerloss. I think it's fine, I don't think a powersurge can make an unnoticable loss in performance, damages should be easy to spot. 

[Needfuldoer]

9 minutes ago, PolishGod said:

Uhh I'm pretty sure clicking shut down shuts down all programs and then the components properly unlike a powerloss.

There's nothing in the hardware that's "prepared" for a shutdown. The motherboard signals the power supply to cut power, and power just unceremoniously ends (except for the trickle that lets the soft power control work).

 

A clean shutdown is all about making sure your software has saved everything it needs to save, and finished writing everything it needs to write, before the power supply shuts off. 

 

Way back in ye olde days, the PC's power switch was literally a power switch, sitting on the hot lead coming from the wall. There was no logic control behind it, so the PC couldn't shut itself off. That's why old versions of Windows would end at a screen like this when you shut down:

 

 

That was Windows telling you it finished all its cleanup, and was ready for you to effectively unplug the PC.

[PolishGod]

3 hours ago, Needfuldoer said:

There's nothing in the hardware that's "prepared" for a shutdown. The motherboard signals the power supply to cut power, and power just unceremoniously ends (except for the trickle that lets the soft power control work).

 

A clean shutdown is all about making sure your software has saved everything it needs to save, and finished writing everything it needs to write, before the power supply shuts off. 

 

Way back in ye olde days, the PC's power switch was literally a power switch, sitting on the hot lead coming from the wall. There was no logic control behind it, so the PC couldn't shut itself off. That's why old versions of Windows would end at a screen like this when you shut down:

 

 

That was Windows telling you it finished all its cleanup, and was ready for you to effectively unplug the PC.

Still safer than a powerloss because powersurges.

[PolishGod]

Ok, this article is pretty useful. https://www.makeuseof.com/effects-power-outages-can-computer/