check how much wattage it can supply
I note he said 1500VA/900W.
If we go by the OP's listed system specs, that system with its R9 5900X, RX 6800 XT, RAM and even with "many" drives and many case fans, a "
quality" 650W PSU could easily support that. But he has a 1200W Siliverstone PSU so even more room to spare. And a decent 1500VA/900W UPS is more than enough to handle most computers, as well as two monitors and network gear too.
It is important to remember that power supplies will demand from the wall (or UPS) only what the computer components demand, plus a little more due to inefficiency. So if the components (CPU, GPU, motherboard, RAM, drives, fans) demand 500W, the PSU will only deliver 500W, regardless if the supply is a 600W, 850W or 1200W supply. That Silverstone is Platinum rated. Assuming at least 90% efficiency, that means with a 500W demand, that supply will only pull from the wall (or UPS) ≈556W (556 x .9 = 500.4).
Even in the VERY RARE event both the OP's CPU and GPU max out demand at the very same point in time, as well as the other components too, maxing out a 650W supply, that 1500VA UPS should be able to handle it.
So I echo AsRock,
any thing else attached to the UPS
Are those "two QHD" monitors attached to the UPS too? What else? Router? Modem? External drives?
Note speakers and printers (especially laser printers) should never be connected to the battery side of a UPS.
Even if the two monitors and network gear is attached to the battery side (which is how my system is connected), that UPS should easily handle the load (assuming all the connected devices are working properly).
@Martin007
when I game I get alarm at random times
Does it just alarm or does it kick over to battery too? Does your computer crash?
As AsRock noted, check your beep codes for a pattern. Then check your UPS's web page or user manual to see of the code provides a clue as to what is happening.
FTR - you should NEVER plug a UPS into a surge and spike protector (SS&P). SS&Ps often just chop off the peaks of excessive surges and spikes and the UPS may see that output (the UPS's input) as "dirty" and error out/flip to battery as a precaution. And you should never plug a S&SP into the battery side of the UPS as the UPS may see that as an unstable load and shut down.
Also, some UPS will report errors if connected to a faulty, mis-wired, or ungrounded wall outlet. So I recommend you make sure yours is properly wired.
Every home and every computer user should have access to a
AC Outlet Tester to ensure the wall outlet is properly wired
and grounded to Earth ground. I recommend one that displays the actual voltage (instead of just LEDs) and a GFCI (ground fault circuit interrupt) indicator as it can be used to test bathroom and kitchen outlets (outlets near water) too. These testers can be found for your type and voltage outlet, foreign or domestic, (like
this one for the UK, or
this one for German outlets) at most home improvement stores, or even the electrical department at Wal-Mart. Use it to test all the outlets in the home or place of work and if a fault is shown, have it fixed by a
qualified electrician.
I find it very useful to have a power meter
I agree. Those can be very useful and informative. That said, many of the better UPSs have an integrated LCD status display panel that can also provide that same information - as well as error codes too.
***
and you need to add all inefficiency of your PSU.
No you don't. That is accounted for in the rating.
If you have a supply rated for 500W supply, it will only draw from the wall (or UPS) 500W. If the computer components demands exceed that (including the amount lost in the form of heat), the supply will [hopefully!] just shut down.
Also for Active PFC you need to use UPS with AVR and best with clean sinusoid
No one needs a pure sinewave UPS for their computers! That is pure marketing hogwash. A quality, sufficiently rated, stepped approximated (simulated, or modified) waveform UPS with AVR is just fine, has been for decades and no reason they are not today - even with active PCF supplies.
Pure sinewave output UPS may be required on highly sensitive, scientific measuring equipment and some very critical life support, medical equipment. But not computers - not even with mission essential servers. Do NOT believe the marketing hype spewed by the makers of pure sinewave UPS.
I am NOT saying don't get a pure sinewave UPS. If the price is right and it otherwise meets your needs, go for it. Just don't dismiss a good stepped approximated sinewave UPS just because it is not a pure sinewave.
If still believing the hype, please read
my post here and follow the links to EVGA and Seasonic (makers of some the best PSUs) and Eaton, one of the most reputable UPS makers and see what they say about using simulated/modified/stepped approximated sinewave UPS.
IMHO UPS without USB connection is really not useful imo as your system will not close automatically on power loss.
100% totally agree! Plus, if interconnection is supported, there usually is monitoring software to go along with it. APC's is called PowerChute. CyberPower's is PowerPanel. These not only let you monitor the UPS status and power usage from your computer, but often let you configure the UPS with several options. The LCD status display, however, allows you to monitor much the same, but your computer does not need to be up and running.