[SOLVED] Seeking UPS recommendations for my first build!

[chrisbenka]

Hi all,

I'm looking for help to find the right UPS for my build. According to Cooler Master's psu calculator, my system's load is 562W, with a recommended PSU wattage of 612W. I actually have a 1200 W PSU 80+ platinum, which I bought as I hope to beef up my specs later down the road. For now, I'm looking for a UPS that meets my system needs at the moment.

I know the recommended formula is typically 1.6 * load wattage , but is there any harm in buying a 1500VA/900W UPS ? How neccessary is an Online UPS? I'm mostly concerned about damage to my RTX 2080ti gpu and Intel 7940x CPU. Also any brand recommendations would be greatly appreciated! Thanks!

 

[Aeacus]

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: http://www.minutemanups.com/support/pwr_un10.php

And here are explanations about the UPS design,
stand-by: http://www.pcguide.com/ref/power/ext/ups/typesStandby-c.html
line-interactive: http://www.pcguide.com/ref/power/ext/ups/typesLineInt-c.html
online: http://www.pcguide.com/ref/power/ext/ups/typesOnLine-c.html

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.

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.

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 1.2kW, at least one monitor is added on top of it. Depending on the monitor size, they use between 23W to 52W. For more accurate power consumption, i need to know your monitor make and model so i can look up it's power consumption. Wi-fi routers don't consume much power. For example, my Cisco EPC3940L consumes 12V at 3A which means 36W.

 

[chrisbenka]

Thanks for your help! My monitor is a Dell 24'' Widescreen Gaming Monitor (SE2417HG). The monitor and pc would be the only components plugged into the UPS as well. I believe the monitor's power consumption is 25W. Do you really think using the PSU's baseline wattage is neccessary or can I just use the load estimate of 612W? The only reason I ask, is because I likely will upgrade my system much later and therefore won't be utilizing the 1200W. In addition I think with my future, desired specs I'll only have a system load of around 900W.

 

[Aeacus]

Yes, your monitor is 25W but i'd consider it 30W which includes safe margin, which would bring the total to 1230W (1200W PSU + 30W monitor).

As far as UPS output goes;
2000VA / 1540W UPS would give you 19 mins of runtime at 600W load,
specs: https://www.cyberpowersystems.com/product/ups/or2200pfcrt2u/

while 1500VA / 1050W UPS would give you 14 mins of runtime at 600W load,
specs: https://www.cyberpowersystems.com/product/ups/or1500pfcrt2u/

and 1500VA / 900W UPS would give you 7 mins of runtime at 600W load,
specs: https://www.cyberpowersystems.com/product/ups/cp1500pfclcd/

That's the difference.

You don't have to go with 1000+W UPS if you don't need more runtime out of your UPS. The 1500VA / 900W UPS i linked last would be more than enough for your current system with 165W CPU (more with OC) and 260W GPU (280W at load, 360W at peak). Your full system combined, with CPU and GPU OC, at peak level, does consume near 600W, so that estimation is about right.

Then again, if you upgrade your system to consume 900W then 1500VA / 900W UPS would give you only 2 mins of runtime at 900W load. Here, i'd go with more powerful UPS off the bat (1500VA / 1050W) rather than buying new UPS down the road.

Note 01: those 3x UPSes i linked above have line-interactive design and they all output true/pure sine wave.
Note 02: they are for USA market only. If you live somewhere else than The States, say so.

In my opinion, every PC should have an UPS.
As far as CyberPower PFC Sinewave series goes (those 3x UPSes i linked above), i too have 2x CyberPower PFC Sinewave series UPSes in use, one for Skylake build, another for Haswell build (full specs with pics in my sig). I have two of these: CyberPower CP1300EPFCLCD (1300VA/780W, true/pure sine wave, line-interactive),
specs: https://www.cyberpower.com/hk/en/product/sku/CP1300EPFCLCD

While my PC is on idle/web browsing, my UPS runtime is about 35 mins. On full load, my UPS can keep the PC running at about 15 mins or so. Then again, my PCs doesn't consume that much power as yours do, hence the far longer runtime. Oh, under the spoiler is combined image of my UPSes, click on spoiler to view.

Spoiler

Top left: After unboxing
Top right: Power-on test
Bottom left: Haswell build UPS in service
Bottom right: Skylake build UPS in service