Question Simulated or Pure Sine Wave UPS for Corsair rm850x psu powered system?

[d99]

Had a string of recent power outages while I was working and gaming, decided I wanted to get a UPS to be able to save my design work or exit out of the game a shut down my pc instead of an immediate black out. I ended up buying a basic simulated sine wave ups from amazon for my system and after doing further research realized that it may not be compatible with my psu. But there are differing views ive found searching around forums, corsairs website and other random places that seem divided on whether this UPS with simulated sine waves will work for a APFC psu. So i wanted to ask y'all if anyone has experience with this and see what I could learn.

 

[Aeacus]

Off the bat: In my opinion, every PC should have an UPS.

UPSes can output 3 different kinds of waveform:
1. square wave - cheapest of the three. ONLY good for robust hardware, like power generators and motors.
2. simulated sine wave (aka stepped-approximated sine wave) - mediocre price. Good for most home appliances (e.g fridge, washing machine, lights).
3. true/pure sine wave - high price. It is the same as you get out of the wall socket. ONLY waveform good for sensitive electronics, like medical equipment, TVs, PC PSUs.

So, to back up PC, you want to have true/pure sine wave UPS. Simulated sine wave UPS may also work, but it may not. More of that below;


When looking for an UPS, there are 2 things to look out:
1. Output waveform (square wave, simulated sine wave and true/pure sine wave)
2. Design (stand-by, line-interactive and online)

From here you can read about the differences between output waveform,
link: https://suvastika.com/why-choose-a-sinewave-inverter-ups/

And here are explanations about the UPS design,
link: https://www.eetimes.com/document.asp?doc_id=1272971

Waveform and design
For PCs, line-interactive UPS would be more than enough since PSUs can easily handle the 2ms to 5ms transfer time of line-interactive UPS.
As far as output waveform goes, true/pure sine wave UPS is best used. While simulated sine wave UPSes are cheaper than true/pure sine wave UPSes, PSUs with Active PFC aren't compatible with simulated sine wave. You might get simulated sine wave UPS running with Active PFC PSU but there can be some major issues. Here's what, how and why.

How do you know which PSUs have Active PFC and which ones don't?
Simple, every PSU that has 80+ certification (e.g 80+ Bronze or 80+ Gold) has Active PFC.

What is Active PFC?
Further reading: https://en.wikipedia.org/wiki/Power_factor#Power_factor_correction_(PFC)_in_non-linear_loads

What can happen when using simulated sine wave UPS with Active PFC PSU?
When simulated sine wave UPS switches over to the battery power, one of 3 things can happen:
1. UPS displays error resulting PC to shut down immediately.
2. UPS shuts down resulting PC to shut down immediately.
3. UPS switches to battery power resulting PC to power off from UPS (PC stays on).

Why it happens?
Simulated sine wave UPS produces a zero output state during the phase change cycle resulting in a power “gap”. This gap may cause power interruption for active PFC PSUs when switching from AC power output to simulated sine wave output (battery mode).

What to do next?
As stated above, your PC can run off from simulated sine wave UPS but be prepared when you face issues with it. When issues do rise, your best bet would be returning the simulated sine wave UPS and getting true/pure sine wave UPS. Or you can go with true/pure sine wave UPS off the bat.

Wattage
As far as UPS wattage goes, you need to consider the power draw of your PC and monitors. Maybe speakers and wi-fi router too if you plan to plug those into the UPS as well. Though, printers, scanners and other such hardware (full list on your UPS manual) don't plug to the UPS since their startup power draw is way too much for UPS to handle and you can fry your UPS.

Taking PSU's max wattage as a baseline is good idea since it will give your UPS more headroom and you can get longer runtime out of your UPS. Since your PSU is 850W, at least one monitor is added on top of it. Depending on the monitor size, they use between 23W to 52W. Wi-fi routers don't consume much power. For example, my Cisco network modem consumes 12V at 3A which means 36W.

Good UPS brands to go for are CyberPower, TrippLite and APC. While there are other UPS brands as well, those three are the best out there.
Note: The more powerful UPS you have, the longer UPS can keep your PC running before it's battery is empty.

To suggest an UPS for you, i need to know your monitor make & model (or part number) + any other piece of hardware make & model you're planning to plug into UPS. Also, i need to know your location (e.g USA, Germany, Italy, Australia etc) so i can suggest UPS with correct power sockets.

 

[d99]

Hi, first of all thank you for this well thought out answer it has been very informative. Im located in the US, have an LG 32 inch 2k 165 hz ultra gear monitor for my main. My secondary is an old msi optixag32cq 2k@144hz that is not as important and honestly on its on its way out with capacitator issues. The LG monitor, pc, and 6e wifi router plus modem would all be on the UPS. Ideally Id like 10/20 minutes of headroom when something occurs, Ive roughly calculated the wattage of my pc to be around 600 w max load . Right now I have a 5800x3d in cpu slot for gaming but I switch it out for a ryzen 9 3900x for work, happens that they both consume the same amount of electricity under load. Just to give as much info as possible here is the build:

CPU
AMD Ryzen 7 5800X3D

RAM
64.0GB Dual-Channel DDR4 @ 1799MHz (16-19-19-39)
Motherboard
ASUSTeK COMPUTER INC. ROG CROSSHAIR VIII HERO (WI-FI) (AM4) 3
Graphics
LG ULTRAGEAR (2560x1440@165Hz)
Optix AG32CQ (2560x1440@144Hz)
4087MB NVIDIA GeForce RTX 4080 (MSI)
Storage
953GB NVMe INTEL SSDPEKNW010T8 (Unknown (SSD))
1863GB Samsung SSD 980 PRO 2TB (Unknown (SSD))
2794GB Seagate ST3000DM 008-2DM166 SATA Disk Device (SATA )
3726GB Seagate ST4000DM 004-2CV104 SATA Disk Device (SATA )

 

[dingo07]

What's the budget for a new UPS?

 

[d99]

$250 is my cutoff ideally

 

[Aeacus]

Ive roughly calculated the wattage of my pc to be around 600 w max load

If you go with 600W/~1000VA UPS, then you're looking ~3 min runtime.

Ideally Id like 10/20 minutes of headroom when something occurs

$250 is my cutoff ideally

With your budget - doesn't happen.

E.g solid UPS (more than enough for your build);
Cyberpower CP1500PFCLCDTAA, 1500VA/1000W, line-interactive, true/pure sine wave,
specs: https://www.cyberpowersystems.com/product/ups/gov-ed-taa/cp1500pfclcdtaa/
amazon: https://www.amazon.com/CyberPower-CP1500PFCLCDTAA-Sinewave-Mini-Tower-Certified/dp/B008U4SBVS

It costs ~$320 but currently on sale on amazon for ~$277. So, over your budget. And if you look the Runtime chart, then you can see that on 600W load, you'll get 7 mins of runtime.

Now, to get 20mins runtime for 600W load, you're looking towards much beefier UPS, e.g:
Cyberpower OR2200PFCRT2U, 2500VA/1540W, line-interactive, true/pure sine wave, rackmount,
specs: https://www.cyberpowersystems.com/product/ups/pfc-sinewave/or2200pfcrt2u/
amazon: https://www.amazon.com/CyberPower-OR2200PFCRT2U-Sinewave-System-Outlets/dp/B003OJAHW0?th=1

Easy 19mins runtime on 600W load, but it will cost you nice $669.
Either mount it into server rack (since it's 2U) or as a tower (should include standing legs).


Though, it seems that you've underestimated the cost of a proper, good quality UPS. Since UPS'es job is to keep your PC running when there's blackout by supplying good and stable electricity to your PC, they also cost a lot of money.
For example, i payed €230 Euros for one of my CyberPower CP1300EPFCLCD (1300VA/780W, true/pure sine wave, line-interactive) UPS and i have two of them in use, one for Skylake build and another for Haswell build (full specs with pics in my sig). That makes $265 USD per one UPS, while your budget is $250 USD.
Since your PC is expensive, it's not easily replaced. Like it or not, if you want the protection, it's not going to be cheap. Though, if you want cheap and good UPS, you need to buy 2x UPSes; 1st the cheap one and 2nd the good one.

So, i advise you to buy good UPS this time around, since you already bought the cheap one.

Though, UPS'es idea (line-interactive topology) is to sustain PC as long as you can save your work and then shut down the PC safely. Usually 5mins is good. Maybe even 10mins.
But UPS is not a battery pack that you can run your PC off at all times. If you want that, buy a gasoline/diesel powered electric generator that provides you electricity when main electricity is off OR online UPS (either double-conversion or delta-conversion topology).

Online UPSes are used to back up entire server parks since online UPS topology is such, where power is constantly taken from the UPS battery and mains is used to recharge the battery. So, when main electricity cuts off, there is 0 transfer time. Only battery level is starting to drain. Downside is, that since battery is in constant use, it wears out more quickly. But online UPSes have several batteries, so, when one fails, the failed one can be replaced without ever cutting the power source to the servers. Oh, and also the fact that online UPSes are maintained by the tech you call on-site. Online UPSes are not user-serviceable (like line-interactive UPSes are).

 

[bill001g]

Of course pure sine wave is always the best. Simulated sign wave should cause no issues with most equipment.

First remember you are only running for few minutes on the simulated sign wave. All the other time the power from the city is just being passed through directly.

If you were running off a generator for long times it is much more a issue. Pure sign wave generators, mostly called inverter generators, are quite a bit more expensive.

Modern pc power supplies to get their high efficiency rating need very clean power. All that really happens is more power is wasted and turned into heat inside the power supply. It also depends what percentage of the total power supplies power you are using. If you are pushing the limits already having dirty power for extended times might cause damage.

Pretty much a UPS is best for those short outages where the lights go out and come back on within seconds. Longer ones give you time to make sure your work is saved.

If you are looking for long term battery run times I would look at equipment designed for solar usage. This equipment is designed to run 24 x7 converting DC power to AC.

Note I have a very old but very large UPS. Since the power output is not very clean I only use it to power the ISP router. It will run for hours and let me have wifi for the cell phone. Found out that it could last 11 hours the last power outage but it caused damage to the batteries so I ended up have to buy almost $200 worth of batteries. Appears to not be the best idea to run these devices outside their normal rated usage.

 

[Aeacus]

Simulated sign wave should cause no issues with most equipment.

Everything outside of sensitive electronics - Yes.

PC's PSU, however, is considered as sensitive electronics and i, personally, would not run simulated sine wave UPS (did explain it's issue above).

If you were running off a generator for long times it is much more a issue.

I believe a distinction must be made here, since solar panels are also considered as generators but output DC, which is turned into AC with an inverter.

But gasoline/diesel powered generators, those usually output square wave. There are simulated sine wave and true/pure sine wave gasoline/diesel powered generators out there as well. But just like true/pure sine wave UPS, those also cost more than square wave or simulated sine wave gasoline/diesel powered generators.

 

[d99]

If you go with 600W/~1000VA UPS, then you're looking ~3 min runtime.


With your budget - doesn't happen.

E.g solid UPS (more than enough for your build);
Cyberpower CP1500PFCLCDTAA, 1500VA/1000W, line-interactive, true/pure sine wave,
specs: https://www.cyberpowersystems.com/product/ups/gov-ed-taa/cp1500pfclcdtaa/
amazon: https://www.amazon.com/CyberPower-CP1500PFCLCDTAA-Sinewave-Mini-Tower-Certified/dp/B008U4SBVS

It costs ~$320 but currently on sale on amazon for ~$277. So, over your budget. And if you look the Runtime chart, then you can see that on 600W load, you'll get 7 mins of runtime.

Now, to get 20mins runtime for 600W load, you're looking towards much beefier UPS, e.g:
Cyberpower OR2200PFCRT2U, 2500VA/1540W, line-interactive, true/pure sine wave, rackmount,
specs: https://www.cyberpowersystems.com/product/ups/pfc-sinewave/or2200pfcrt2u/
amazon: https://www.amazon.com/CyberPower-OR2200PFCRT2U-Sinewave-System-Outlets/dp/B003OJAHW0?th=1

Easy 19mins runtime on 600W load, but it will cost you nice $669.
Either mount it into server rack (since it's 2U) or as a tower (should include standing legs).


Though, it seems that you've underestimated the cost of a proper, good quality UPS. Since UPS'es job is to keep your PC running when there's blackout by supplying good and stable electricity to your PC, they also cost a lot of money.
For example, i payed €230 Euros for one of my CyberPower CP1300EPFCLCD (1300VA/780W, true/pure sine wave, line-interactive) UPS and i have two of them in use, one for Skylake build and another for Haswell build (full specs with pics in my sig). That makes $265 USD per one UPS, while your budget is $250 USD.
Since your PC is expensive, it's not easily replaced. Like it or not, if you want the protection, it's not going to be cheap. Though, if you want cheap and good UPS, you need to buy 2x UPSes; 1st the cheap one and 2nd the good one.

So, i advise you to buy good UPS this time around, since you already bought the cheap one.

Though, UPS'es idea (line-interactive topology) is to sustain PC as long as you can save your work and then shut down the PC safely. Usually 5mins is good. Maybe even 10mins.
But UPS is not a battery pack that you can run your PC off at all times. If you want that, buy a gasoline/diesel powered electric generator that provides you electricity when main electricity is off OR online UPS (either double-conversion or delta-conversion topology).

Online UPSes are used to back up entire server parks since online UPS topology is such, where power is constantly taken from the UPS battery and mains is used to recharge the battery. So, when main electricity cuts off, there is 0 transfer time. Only battery level is starting to drain. Downside is, that since battery is in constant use, it wears out more quickly. But online UPSes have several batteries, so, when one fails, the failed one can be replaced without ever cutting the power source to the servers. Oh, and also the fact that online UPSes are maintained by the tech you call on-site. Online UPSes are not user-serviceable (like line-interactive UPSes are).

I can definitely justify going $50 increase in price, originally befreo coming to that $250 I was up in the 300s, I was figuring how much would I spend to protect my pc from these brown outs and roughly 10% seemed adequate. I jumped the gun and bought the simulated sine wave before doing proper research. What I will do now is return that, use the credit for it and buy that Cyberpower CP1500PFCLCDTAA, 1500VA/1000W, line-interactive, true/pure sine wave that you mentioned. 5-7 minutes sound like enough time to save work and power down my machine most of the time. When i said 10-20 I wasnt understanding how much money itd take

 

[d99]

This has been extremely informative and helpful, thank you all for taking the time to respond to my question in a professional manner. Ended up learning a bit from the whole thing and will now make an informed purchase after returning the simulated sine UPS