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I have a pretty power hungry rig, enough that I threw an 850w PSU in there. I've played around with a few wattage estimation/calculator sites and they've all suggested I would need at least 650-750w PSU in the first place, so my usage is definitely "up there."

To make a long story short, the UPS I have now simply isn't cutting it. With recent power outages, it's getting a surge and just dying immediately, and I can only assume it's overloaded (and I believe the light flashes "overload" when it does happen).

The current UPS I use is an APC XS 900 (900VA, 540W), so I can put two and two together to figure that it's a problem, but here's the question:

Seeing as the max wattage my PSU would be using is 850w, and considering the power it uses is never actually going to be that high, can I get away with APC's 1500VA version (1500VA, 865w)?

It seems to be the only relatively affordable UPS for a wattage above my PSU. I don't intend to put more load on the UPS, as I already have another strictly for the monitor and other electronics.

I appreciate any advice.

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closed as too localized by BloodPhilia, digitxp, slhck, Nifle, Sathya Aug 29 '11 at 7:55

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I don't trust any UPS with the surge protection. Hook yours up to a dedicated surge protector. – digitxp Aug 28 '11 at 17:17
Its not only a matter of enough watts to prevent a hard shutdown, but how long you expect it to stay up while on the UPS. Buy all you can afford. – Moab Aug 28 '11 at 17:24
@digitxp - Do any surge protectors work!? I have had PSUs that have had surges and broken despite being on one... I can't argue that one built in to a UPS is any better/worse, but, IMHO, many surge protectors don't do their job. – William Hilsum Aug 28 '11 at 17:30
@Wil Surge protectors work like lightbulbs. They burn out an have to be replaced. – digitxp Aug 28 '11 at 17:38
up vote 2 down vote accepted

+1 for @Moab's comment... This one meets your specifications, but, if it was me - get any UPS that has a USB/serial port for computer control, and simply set it to shut down your PC after ~ 2 minutes of no power.

That being said, again as Moab said, if you have more money and want uptime on power outages, buy a better one.

I personally use several 650VA UPSs here and do something similar to what I say above, they have enough power to keep my PC on for 5-10 minutes, I often have (at least twice a month) brown outs or power drops that last for about 20 seconds and this ensures that my machines stay up and on.

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The concern isn't really the amount of time they'll run. Quite often the power here will go out very briefly and come back on instantly. As long as I have the power on for that brief second, or a couple minutes to shut down if it's worse, that's all I need. – scrot Aug 28 '11 at 19:32
@scrot ... exactly my thinking / why I have a UPS here! – William Hilsum Aug 28 '11 at 19:34

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