How much wattage do I need? (UPS)

[Zalosath]

Hi!

 

Looking to buy a UPS for a home server, just wondering how much wattage I might need for it? The PSU is 550 Watts but I doubt it ever actually uses that much. Specs for that system:

 

550 Watt Corsair PSU

B450M DS3H

64GB LPX 

R5 5600G

Intel ARC A380

16TB EXOS

1 TB SSD

512GB NVME

 

What should I be looking for in terms of wattage? Is it as simple as "well, you need 550 watt or more"? I've also seen some mention of VA, will that come into play or does that directly correlate with wattage?

 

Any advice appreciated! New to this area, as you can tell! Let me know if you need more info.

[Kid.Lazer]

Are you looking to keep the system running for an extended period of time during an outage, or just enough time for you to safely shut it down?

[Zalosath]

Just now, Kid.Lazer said:

Are you looking to keep the system running for an extended period of time during an outage, or just enough time for you to safely shut it down?

Just enough for a safe shutdown is fine. Maybe 2 minutes tops?

[Kid.Lazer]

For that usage, you don't need much at all. For my HTPC setup (see signature), I use this guy. It's slimmer than most units, and the top plugs allow me to access everything even when jammed behind my entertainment center. I get more than enough time to do a safe shutdown, or drag my generator out to get my house back up and running.

 

And I use this one for my all my network gear and NAS.

 

It won't hurt to go bigger if you can afford it, but (as you probably already noticed) the price tends to climb pretty fast as you jump up to higher-performing units.

[manikyath]

first i gotta address VA, because it is extremely misunderstood..

 

"watts" is the amount of power consumed, and "VA" is the amount of power that's transferred trough the cabling (and by extension, your UPS. these differ a given amount depending on the load's "power factor", essentially the worse the power factor is the larger the difference is.

 

the reason why UPS manufacturers express capacity in VA, is because they have to build the circuitry to handle that much VA...

 

but with that said.. they have a "watts" limit too, for my brand of choice (APC) this is usually at abou thalf or just above half of the VA rating. 

 

---

 

having ALL that said.. in my experience the biggest problem with a UPS for a home server is runtime, and the lifespan of the lead-acid battery. first off, units with a 12 volt battery will absolutely MURDER that battery every time they need to kick in, my 12 volt unit needs a battery swap about 4x faster than my 24 volt units. and the more worn the battery is the shorter your runtime is, quite exponentially so.

 

what i suggest doing is buying one of those plug-in-the-wall watt meters, and testing how much power your server uses 'worst case' (i.e. load it down with applications.)

 

then you take that power usage, and look up the 'runtime graphs' of vareous UPS models. if you cant find a runtime graph, assume runtime is ass.

 

look for a model that has following features:

- at least 30 minutes runtime on a fresh battery, on a worst case power requirement for your server.

- 24 volt battery

- ideally full sine wave, but my stepped sine wave units have been doing fine.

 

 

[Zalosath]

45 minutes ago, Kid.Lazer said:

-snip-

 

37 minutes ago, manikyath said:

-snip-

 

 

Thanks both. I'll get a plug-in-wall meter and check what I actually need, should I factor in any amount as a just in case? +-50-100VA?

[Agall]

1 hour ago, manikyath said:

first i gotta address VA, because it is extremely misunderstood..

 

"watts" is the amount of power consumed, and "VA" is the amount of power that's transferred trough the cabling (and by extension, your UPS. these differ a given amount depending on the load's "power factor", essentially the worse the power factor is the larger the difference is.

 

the reason why UPS manufacturers express capacity in VA, is because they have to build the circuitry to handle that much VA...

 

but with that said.. they have a "watts" limit too, for my brand of choice (APC) this is usually at abou thalf or just above half of the VA rating. 

 

---

 

having ALL that said.. in my experience the biggest problem with a UPS for a home server is runtime, and the lifespan of the lead-acid battery. first off, units with a 12 volt battery will absolutely MURDER that battery every time they need to kick in, my 12 volt unit needs a battery swap about 4x faster than my 24 volt units. and the more worn the battery is the shorter your runtime is, quite exponentially so.

 

what i suggest doing is buying one of those plug-in-the-wall watt meters, and testing how much power your server uses 'worst case' (i.e. load it down with applications.)

 

then you take that power usage, and look up the 'runtime graphs' of vareous UPS models. if you cant find a runtime graph, assume runtime is ass.

 

look for a model that has following features:

- at least 30 minutes runtime on a fresh battery, on a worst case power requirement for your server.

- 24 volt battery

- ideally full sine wave, but my stepped sine wave units have been doing fine.

 

 

Even then, the discussion on the power triangle is even more complex. Let alone a discussion between line-interactive and double conversion type UPS.

 

2 hours ago, Zalosath said:

Hi!

 

Looking to buy a UPS for a home server, just wondering how much wattage I might need for it? The PSU is 550 Watts but I doubt it ever actually uses that much. Specs for that system:

 

550 Watt Corsair PSU

B450M DS3H

64GB LPX 

R5 5600G

Intel ARC A380

16TB EXOS

1 TB SSD

512GB NVME

 

What should I be looking for in terms of wattage? Is it as simple as "well, you need 550 watt or more"? I've also seen some mention of VA, will that come into play or does that directly correlate with wattage?

 

Any advice appreciated! New to this area, as you can tell! Let me know if you need more info.

Find the highest VA rated unit for $90-$100 in your region and stick to that. Regarding necessity, a 450VA would likely be just fine, but if you can go higher, then I would. I think the $100 price point is where you'd want to look, since you get sufficient ports, features, and quality to potentially use it elsewhere if you end up upgrading it later, like as a UPS for your modem+router if that's not nearby.

[Zalosath]

On 3/8/2024 at 5:55 PM, manikyath said:

first i gotta address VA, because it is extremely misunderstood..

 

"watts" is the amount of power consumed, and "VA" is the amount of power that's transferred trough the cabling (and by extension, your UPS. these differ a given amount depending on the load's "power factor", essentially the worse the power factor is the larger the difference is.

 

the reason why UPS manufacturers express capacity in VA, is because they have to build the circuitry to handle that much VA...

 

but with that said.. they have a "watts" limit too, for my brand of choice (APC) this is usually at abou thalf or just above half of the VA rating. 

 

---

 

having ALL that said.. in my experience the biggest problem with a UPS for a home server is runtime, and the lifespan of the lead-acid battery. first off, units with a 12 volt battery will absolutely MURDER that battery every time they need to kick in, my 12 volt unit needs a battery swap about 4x faster than my 24 volt units. and the more worn the battery is the shorter your runtime is, quite exponentially so.

 

what i suggest doing is buying one of those plug-in-the-wall watt meters, and testing how much power your server uses 'worst case' (i.e. load it down with applications.)

 

then you take that power usage, and look up the 'runtime graphs' of vareous UPS models. if you cant find a runtime graph, assume runtime is ass.

 

look for a model that has following features:

- at least 30 minutes runtime on a fresh battery, on a worst case power requirement for your server.

- 24 volt battery

- ideally full sine wave, but my stepped sine wave units have been doing fine.

 

 

I got a watt meter and it says that at a pretty decent load (GPU transcoding 4K 120Mbps, full stress test on CPU), I was reaching about 140 Watts. If I account for that and just go with a 450VA, do you think that'll work fine? That should give me some overhead in case of a future upgrade or whatever.

[manikyath]

4 hours ago, Zalosath said:

I got a watt meter and it says that at a pretty decent load (GPU transcoding 4K 120Mbps, full stress test on CPU), I was reaching about 140 Watts. If I account for that and just go with a 450VA, do you think that'll work fine? That should give me some overhead in case of a future upgrade or whatever.

how many watts can the 450VA model provide?