UPS for a moderately high power system?

sphinx99

[H]ard|Gawd
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Since upgrading to a 4090, my system is starting to trip the overcurrent protection on my UPS (a cyberpower 1500VA unit, one of the PFC sine wave ones) under synthetic benchmarking of the CPU and GPU simultaneously. I don’t think this is a use case that I am going to experience under normal usage, so I am most likely going to let it slide. That said, it did occur to me that the battery in this unit is relatively new and rate capability may diminish over time.

Wanted to check in if anyone here is using larger-than-1500-class UPSs at home. My system is a TR3+4090+many cards and peripherals. PSU is a Seasonic TX 1KW that is powering the system quite well, even under max benchmarking, with overclocking of both the CPU and GPU.
 
The issue is that, at least AFAICT in the US, any UPS larger than a 1500 VA unit is going to require special AC wiring. A normal 120 V / 15 A circuit simply can't adequately support a larger unit, which typically require at minimum a 20-30 A circuit and often 240 V. So unless you want to unplug your clothes dryer to use your PC or hire an electrician to run a new line, your current UPS may have to do.

The state of the battery isn't relevant. Consumer UPS units don't pull from it unless the AC is actually out. And assuming you've connected the UPS's USB to the PC, it should be possible to drop the PC into a low-power state that'll give you enough time to save and shut down.
 
1500W is the maximum sustained draw from a standard NEMA 5-15 outlet and 1500VA units are the largest consumer size as a result. A 20A 120V 5-20 outlet and a 2000VA unit would be a intermediate point between 5-15 and a 240V outlet; depending on your wiring might just require a new receptacle.

OTOH I'm surprised a 1000W PSU is generating spikes big enough and long enough to trip a 1500VA UPS.
 
Could you run a dual psu system and put each psu on a different circuit?
 
Yeah not going to worry about it. After 20 years researching battery chemistry I'm pretty sure this is an UV alarm due to voltage collapse as a result of an old battery. I'm just going to replace it or swap to something hand-built.
 
This is getting over complicated pretty quick...

Stick with the ups you have and don't worry about it :)
I ask because I've been thinking of going to dual fanless PSUs and I do wonder about load balancing the draw among different circuits (I have a lot of gear in my office including a portable A/C)
 
I have a 1500VA APC with a 4090, 2x27” 1x34” OLED and it doesn’t trip
 
Maybe undervolting / power limiting the 4090 is a solution. Decent power savings with minimal performance loss depending on how much you go for.
 
Since upgrading to a 4090, my system is starting to trip the overcurrent protection on my UPS (a cyberpower 1500VA unit, one of the PFC sine wave ones) under synthetic benchmarking of the CPU and GPU simultaneously. I don’t think this is a use case that I am going to experience under normal usage, so I am most likely going to let it slide. That said, it did occur to me that the battery in this unit is relatively new and rate capability may diminish over time.

Wanted to check in if anyone here is using larger-than-1500-class UPSs at home. My system is a TR3+4090+many cards and peripherals. PSU is a Seasonic TX 1KW that is powering the system quite well, even under max benchmarking, with overclocking of both the CPU and GPU.
Most of these units will raise alarm at 900-1000W draw from their outlets.
You can look into a larger unit (2-3kVA) which does require a larger circuit however you can run it on a 15A circuit as you're not exceeding the max power. Just remember not to add more things to the UPS then you have now. These models (ex. APC SmartUPS) also feature extended runtime options too. They're not cheap but if your power is unstable it's really not an option to run without one.
 
Most of these units will raise alarm at 900-1000W draw from their outlets.
You can look into a larger unit (2-3kVA) which does require a larger circuit however you can run it on a 15A circuit as you're not exceeding the max power. Just remember not to add more things to the UPS then you have now. These models (ex. APC SmartUPS) also feature extended runtime options too. They're not cheap but if your power is unstable it's really not an option to run without one.
Thank you. I realized the consumer units I am using are alarming around 1000W so I may need to upsize.
 
Also remember that's during synthetic loads. Real world is very different.
 
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