[SOLVED] Recommended UPS VA for my PC ?

Bugasboy

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Sep 8, 2020
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Hello good day, I hope you're all well. I have a question regarding the VA amount for UPS.

My specs:
PSU:Seasonic FOCUS GX-750 GOLD
GPU: RTX 3070 PALIT JET STREAM
CPU: AMD Ryzen 5 5600X
COOLER: NOCTUA NH-D15
RAM: 2x8 G.SKILL TRIDENT Z NEO
STORAGE: Colorful SL500 1 TERA SSD and 500 GBST3500413AS HDD
MOTHERBOARD: MPG B550 GAMING CARBON WIFI (MS-7C90)
MONITOR: ASUS VG248

With this pc, what UPS should I get?
 
Solution
You likely only need 1350 but a 1500 does not cost a lot more. These are 2 example of a popular brand, note these are both sign wave models.
The main difference is the 1350 is only rated to handle 800 watts which is still more than you can use even if you were running at maximum load. I suspect you are using much less.
The 1500 is rated to 1000 watts.

The other difference is the 1500 has 2 12 volt 9ah batteries where the 1350 has 7ah. What is kinda the scam is in 3 years when you need to replace the batteries you can put 9ah batteries in the 1350 unit, they are the same physical size. It will still only be 800 watts but last much longer.
The difference in cost is only about $2 for the batteries with more power, so I don't...
Be nice if there was just 1 number you could look for.

The first thing to figure out how much power you are actually using. Even though your pc has a 750 watt power supply it is not likely you are using that much.

Most people think of power in watts not VA. They are related but there is some variation so you need to read the actual specs.

Worst case if you machine actually was using 750watts you need to look at say at least 1000va model but more likely it will have to be 1200va. Check the actual watt rating.

Unfortunately this just tells you how much power a UPS can provide but has nothing to do with how long it can provide it running off the battery. That is purely related to the number and size of the batteries in the unit. For example a large unit with a extended battery pack will last much longer than a very small unit with a small battery even though they have exactly the same VA/WATT rating. Best bet when you compare is look up the specs on the replacement batteries for the unit. You can then guess the difference in how long units will last. More and larger amp hour batteries last longer.

The other thing you need to watch for is you will need what is called a sign wave UPS. Modern computer power supplies because they have become very efficient now require very clean power. Using cheap non sign wave UPS can damage power supplies.
 
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What is the purpose of the proposed UPS?
Is it just to tide you through a momentary power glitch?
Or, is in intended to allow you to run for an extended time during a power outage?

APC will have a calculator to estimate what you might need.
The problem with calculators is entering correct and relevant data.

If it will help, I use a APC 1500. See my sig for what it manages.
APC has a nifty app(PowerChute) that shows run time. As I type, it is showing 26 minutes using some 200w. Under heavy load, I recall it going up to about 450w so that would give me sufficient time to gracefully shut down.
It last went to battery power due to electrical noise on 12/17/2022
I use about 3.3 kwh per day.
All nice stuff to know.
 
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Bugasboy

Commendable
Sep 8, 2020
26
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1,535
What is the purpose of the proposed UPS?
Is it just to tide you through a momentary power glitch?
Or, is in intended to allow you to run for an extended time during a power outage?

APC will have a calculator to estimate what you might need.
The problem with calculators is entering correct and relevant data.

If it will help, I use a APC 1500. See my sig for what it manages.
APC has a nifty app(PowerChute) that shows run time. As I type, it is showing 26 minutes using some 200w. Under heavy load, I recall it going up to about 450w so that would give me sufficient time to gracefully shut down.
It last went to battery power due to electrical noise on 12/17/2022
I use about 3.3 kwh per day.
All nice stuff to know.

My purpose for the UPS is to safely shutdown my pc during a power outage because of the place that I am living, brownouts are frequent.
 

Bugasboy

Commendable
Sep 8, 2020
26
2
1,535
Since your pc power usage is not minimal, going for 90 minutes run time will be expensive.

Oh I only need like minimum 5 to maximum 10 minutes to save all my work since I'm still a student, I necessarily don't need that much run time. With this being said, is a 1500 VA UPS an overkill or just enough?
 
Last edited:
You likely only need 1350 but a 1500 does not cost a lot more. These are 2 example of a popular brand, note these are both sign wave models.
The main difference is the 1350 is only rated to handle 800 watts which is still more than you can use even if you were running at maximum load. I suspect you are using much less.
The 1500 is rated to 1000 watts.

The other difference is the 1500 has 2 12 volt 9ah batteries where the 1350 has 7ah. What is kinda the scam is in 3 years when you need to replace the batteries you can put 9ah batteries in the 1350 unit, they are the same physical size. It will still only be 800 watts but last much longer.
The difference in cost is only about $2 for the batteries with more power, so I don't know why they don't sell them with that to begin with.



Note they do actually sell av1500 units that can run 1500 watts but they cost more than double the price.

There are many other brand that will work as good. Just be sure you are buying true sign wave units.


A addition comment. Most better UPS also have the ability to boost the power without actually running on the batteries if the voltage drops just a small amount for long periods of time. If it drops below some value it will then move to the battery.
 
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