Help choosing UPS...

Toggle sidebar Toggle sidebar
L

Lou01_01

Distinguished
Jul 11, 2010
14
0
18,510
Hi, everyone!

I live in Rio de Janeiro, where the offer of decent and continuous electricity is an issue since the first lines were placed ages ago... I already had some really bad events with sudden interruptions of power supply, burning several electronic devices and making us embark on the saga of redtape involving the refund from the energy company...

I've moved a few years ago to a new neighborhood, where the power supply is even more neglected, with outages during daytime with clear skies and no apparent or understandable reason. When it rains, things get even worse, with many short interruptions followed by voltage spikes when it comes back. Since then, I've been using UPS units to help keeping my PC "unharmed", but the one I'm using at the moment seems to be weak for my specs.

I'm aware (I believe I've already read more than fifty polls regarding this...) that UPS units that do not offer pure sine waves are bad for PFC active PSU's - which is my case. I have a Corsair 750TX. My actual config is supported by a 1300VA brazillian SMS UPS unit, whose power factor (sadly, I only found out about this after buying this crap...) is only 0.5, which provides only 650W for my rig. I know it's less than I need, and so does my PC, who started to power off even with the slightest voltage oscilation when I play heavier games, such as BF3 or other hardware demanding titles. But when I'm working with smaller loads, it holds things up for enough time so I can power off the system the way it's meant to be done, what makes me believe it's working as it should, even overloaded.

I already have a UPS model in mind - the APC BR1500G / 865W, - which I intend to use only with my PC and monitor (23" LCD), hope it is enough. I only want to have some two or three minutes (at most) to be able to save a project and power off my system the best way possible without losing my job (I study Architecture and spend hours working on them). I can't afford a pure sine wave UPS unit at the moment, since they are OUTRAGEOUSLY expensive down here in Brazil, and since I don't want to work continuosly during power outages...

Any of you guys using this particular UPS on your rigs?? Or any similar ones, who could give me some feedback on the unit performance using a system spec somewhat like mine?? My full specs are show below:

Mobo - Gigabyte 890FXA-UD5
PSU - Corsair TX750W
GPU - MSI GTX 560Ti Twin Frozr II
Memory - 12GB DDR3 (2x2GB + 2x4GB)
CPU - AMD Phenom II X6 1090T 3,2GHz (OC to 3,6GHz)
CPU cooler - Corsair A70
Monitor - Samsung 23" Syncmaster S23B550 LCD screen

Any help will be more than welcome!! Thx in advance!!


 
Solution
S
A power supply that is 80% efficient (80 Plus certified) will draw it's rating plus an additional 20% from the outlet. For example, a 1000watt power supply with an efficiency rating of 80%, would draw 1200watts from the wall outlet.

To determine the maximum potential load, you'd typically determine the maximum output rating of your power supply...in this case, 750watts. You'd then determine the efficiency rating, in your case it's 85%. So, 750watts would be 85% of the power drawn from the wall outlet, leaving 15% unaccounted for. Well, 15% of 750watts is 112.5watts. The maximum potential power draw for your computer is 862.5watts. With your configuration, you'll never actually reach that power draw. The 2 most power hungry...
Sort by date Sort by votes
S

sykozis

Distinguished
Dec 17, 2008
1,759
5
19,865
When buying a UPS, you need to determine the maximum potential power draw of the devices being connected to the UPS. You need to find a UPS that meets or exceeds the maximum potential power draw of the devices that will be connected to it. Overdrawing a UPS can cause component damage....either to the UPS or the devices connected. With your particular configuration, the APC BR1500G should be fine as I don't see you maxing out your power supply. You should only be putting a 600-650watt load, maximum, on the UPS with the specifications you've stated.

I don't know what is available in Brazil, but if possible, I'd recommend looking at CyberPower UPS. They're just as good as APC but usually considerably cheaper.
 
Upvote 0 Downvote
L

Lou01_01

Distinguished
Jul 11, 2010
14
0
18,510
Dear sykozis, thank you for your reply!

Down here in Brazil, there are very few brands to choose from, and I've never seen Cyberpower among them. APC is one of the few foreign brands currently being sold, and I think some of their models are already assembled here to make them more affordable. Anyway, I feel more confident of my future purchase now, thx again!
 
Upvote 0 Downvote
L

Lou01_01

Distinguished
Jul 11, 2010
14
0
18,510
I have been researching about this subject for a few days (if I had done this before, I wouldn't have bought the UPS I'm using now...), and have been intrigued by the fact of the average 80% usage on most PSU's. What about the remaining 20%? Are they meant for some kind of protection? Are they taken into consideration when we calculate the maximum load of the entire system, and consequenty, when we calculate the necessary power for the UPS unit?
 
Upvote 0 Downvote
S

sykozis

Distinguished
Dec 17, 2008
1,759
5
19,865
A power supply that is 80% efficient (80 Plus certified) will draw it's rating plus an additional 20% from the outlet. For example, a 1000watt power supply with an efficiency rating of 80%, would draw 1200watts from the wall outlet.

To determine the maximum potential load, you'd typically determine the maximum output rating of your power supply...in this case, 750watts. You'd then determine the efficiency rating, in your case it's 85%. So, 750watts would be 85% of the power drawn from the wall outlet, leaving 15% unaccounted for. Well, 15% of 750watts is 112.5watts. The maximum potential power draw for your computer is 862.5watts. With your configuration, you'll never actually reach that power draw. The 2 most power hungry components in your system are your processor and graphics card, which combined should draw less than 400watts. Your monitor should be in the range of 26-38watts. Taking into account other components in your system, you should see a maximum draw, from the UPS itself, of approax 600-650watts at absolute maximum.

Since the likelihood of your system actually reaching the 750watt rating of your power supply, theoretical draw is sufficient but it's still recommended that your UPS can provide more power than the PSU is rated for.
 
Upvote 0 Downvote
Solution
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom