UPDATE 2 | Fixed input lag and floaty mouse with UPS

[Slender]

Have you tried getting a completely new PC and mouse first before using a double conversion UPS? Maybe your PC has permanent damage from the power issues the plagued the computer for however long it's plagued it for.

No,its no help

You haven’t tried it? I feel like you should. I really do think that it’ll fix the issue. A double conversion UPS gives clean power regardless of input quality. If a UPS can work perfectly for IT equipment, medical equipment and mission critical equipment which is the most sensitive to power issues, then something as simple as a PC setup should work fine. The companies of these USPs test these on stuff as simple as lightbulbs and everything work flawlessly. Trust me bro, if you still have your UPS keep it and then switch the PC and anything else that has been affected by the EMI and then everything should work flawlessly for you after that.

cmon, its 2026 already, devices like UPS, power conditioners etc.. do nothing to our problem. We know that problem is shared dirty neutral with low grounding or none grounding

and that affect on battery devices too

[jterri]

Have you tried getting a completely new PC and mouse first before using a double conversion UPS? Maybe your PC has permanent damage from the power issues the plagued the computer for however long it's plagued it for.

No,its no help

You haven’t tried it? I feel like you should. I really do think that it’ll fix the issue. A double conversion UPS gives clean power regardless of input quality. If a UPS can work perfectly for IT equipment, medical equipment and mission critical equipment which is the most sensitive to power issues, then something as simple as a PC setup should work fine. The companies of these USPs test these on stuff as simple as lightbulbs and everything work flawlessly. Trust me bro, if you still have your UPS keep it and then switch the PC and anything else that has been affected by the EMI and then everything should work flawlessly for you after that.

cmon, its 2026 already, devices like UPS, power conditioners etc.. do nothing to our problem. We know that problem is shared dirty neutral with low grounding or none grounding

How do I know that my house has good grounding? Is there a way for me to check?

[MK92]

Grouding is NOT important, I even tried this in another house where my PC works fine, i temporary disconnected ground wire in socket and used only two wires, and the PC still worked perfectly fine...do you know what ground even does? The ground wire is not active and carries no current during normal operation (unless you have TN-C, then its combined with neutral as PEN)...the only time when anything would run through ground wire is when there is a short circuit, until that it's just a wire with no function, no operation and cannot do anything to PC.

The problem, as someone above said, is dirty current coming in from neighbours through shared neutrals (or even directly from substation's neutral), and high impedance of wiring...UPS cannot fix neutral and wiring problems, the problem is not "EMI", it never was.

[dervu]

Grouding is NOT important, I even tried this in another house where my PC works fine, i temporary disconnected ground wire in socket and used only two wires, and the PC still worked perfectly fine...do you know what ground even does? The ground wire is not active and carries no current during normal operation (unless you have TN-C, then its combined with neutral as PEN)...the only time when anything would run through ground wire is when there is a short circuit, until that it's just a wire with no function, no operation and cannot do anything to PC.

The problem, as someone above said, is dirty current coming in from neighbours through shared neutrals (or even directly from substation's neutral), and high impedance of wiring...UPS cannot fix neutral and wiring problems, the problem is not "EMI", it never was.

So what is dirty current if not EMI?

[MK92]

Fluctuations, too low voltage, impedance, harmonics, floaty shared neutral carrying your neighbour's voltages...this all goes under "dirty electricity", it is never classic "EMI" causing problems, if your problem would be EMI, then a single ferrite choke would make all problems disappear.

EMI would only affect monitors (like visible image and color distortion, flickering, those visible lines "traveling" through monitor etc.) and audio equipment (buzzing, hissing, crackling etc.). It CANNOT cause problems with frame pacing, frame choppiness, refresh rate inconsistency, internal Windows compositor timing etc., which we perceive as a feeling like it's below 60hz refresh rate, floaty mouse, choppiness and lagging of everything...this is caused by neutral wires and nothing else.

[Slender]

Fluctuations, too low voltage, impedance, harmonics, floaty shared neutral

why all of that doesnt fixed by battery mode?

[MK92]

But it is fixed? You are either having online UPS doing double conversion in battery mode while still connected to the wall (and therefore still using building neutral, even if battery mode is ON), or you have connected only PC to the battery and not monitor+modem as well. For me it works, but i cannot get more than 5-10 mins having PC and monitor and modem all on a battery, so its pointless.

[f1ndus]

But it is fixed? You are either having online UPS doing double conversion in battery mode while still connected to the wall (and therefore still using building neutral, even if battery mode is ON), or you have connected only PC to the battery and not monitor+modem as well. For me it works, but i cannot get more than 5-10 mins having PC and monitor and modem all on a battery, so its pointless.

Only good and proper grounding is way how to deal with this problem.
Yes it is probably becouse of shared neutral i think 99%.
But becareful, when u do your grounding and "fix" you need to wait couple of days maybe when your PC stabilize after he was too long used in this dirty electricity, maybe its permament sometimes IDK. But some people i know they did good grounding but they had still problems until they bought new pc and eqiupments

[MK92]

But it is fixed? You are either having online UPS doing double conversion in battery mode while still connected to the wall (and therefore still using building neutral, even if battery mode is ON), or you have connected only PC to the battery and not monitor+modem as well. For me it works, but i cannot get more than 5-10 mins having PC and monitor and modem all on a battery, so its pointless.

Only good and proper grounding is way how to deal with this problem.
Yes it is probably becouse of shared neutral i think 99%.
But becareful, when u do your grounding and "fix" you need to wait couple of days maybe when your PC stabilize after he was too long used in this dirty electricity, maybe its permament sometimes IDK. But some people i know they did good grounding but they had still problems until they bought new pc and eqiupments

Nonsense, your PC cannot get "infected" by bad electricity, unless your PSU is already physically damaged and worn out because of being exposed to harmonics for a long time, so you would just need to replace the weak PSU and not entire PC.

You said "But some people i know they did good grounding but they had still problems until they bought new pc and eqiupments " - what is the chance that they never have electricity problems at all, but just weak PSU? Maybe there were small fluctuations and a little bit of electric noise, yes, but in the end it was the weak PSUs fault...any older standard below ATX 3.0 are known for being very sensitive to non-clean electricity, it would produce high ripple, low transient response etc.

And as I said in one of the previous posts, grounding is not important - you don't even need grounding for PC to work perfectly, as I tested it with no ground wire in a house where electricity is fine and it worked with no problems. The problem is shared neutral wire and noise on it, yes...not 99%, but 100%...even the small LED lamps are injecting big noise into the shared neutrals, now imagine people also running air conditioners, induction hobs, computers and basically everything else with switching power supplies, water heaters, washing machines, water pumps, old fridges working 24/7 etc...if you are in older apartment, all this noise goes directly into your socket through shared neutrals.

[Yazeedtt]

This issue is complex, and people’s experiences differ. Some attribute their problem to a bad neutral line or electrical issues when they might actually be dealing with something else. However, I’ve become convinced that the problem is electrical and not EMI or anything else.

After I tested by draining my phone battery to 0% and then charging it in another house, the difference became clear—how smoothly and normally it works there compared to how slow my phone browsing is at home. It becomes slow when it’s charged at home and used, and there’s also strange behavior while using the phone during charging.

All of this is enough evidence for me. It’s a very complex issue, and I apologize for my language since I’m using a translation tool.