how match va ups i need to hold this system for 5mins

[sarigan2003]

what ups i must pick this is my specs

monitor lg flatron ips 236v
mobo asus rog 370f
cpu ryzen 1700
gpu gtx 1070ti
memory 16gb
psu seasonic 550 gold+
3ssd drives
1hdd drive

please tell me how match va i need to support this system on power loss for 5min maximum
also sugest me any model im open to sugestions since is my first ups, thx u all for yor time

 

[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
With UPS, you need to consider the power draw of your PC and monitor. 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.

Since your monitor uses 36W, let's consider 50W for monitor to be safe. Your PC, at max load, should consume around 380W (GTX 1070 Ti is 180W + rest of the system is about 200W). But just to be safe and give UPS some headroom, let's consider PC's power draw the same as PSU output wattage, which is 550W. Add monitor to it with safe margin and you'd be looking towards 600W UPS. As far as VA for UPS goes, 600W UPSes are usually rated 1000VA.

Good UPS brands to go for are CyberPower, TrippLite and APC.
Note: The more powerful UPS you have, the longer UPS can keep your PC running before it's battery is empty.

Without knowing your location, it's hard for me to suggest UPS model to go for. E.g if you're from the States, you'll need an UPS that works in 120V current but if you live e.g in Europe, you'll need UPS that works on 240V current. Also, knowing your budget will also help.