# Is this a reasonable load % for a PC with a UPS? **URL:** \ **Category:** Factual Questions\ **Created:** [February 23, 2009, 11:53pm UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125 "2009-02-23T23:53:57Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [February 23, 2009, 11:53pm UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/1 "2009-02-23T23:53:57Z")
I’ve got a desktop PC with a 3 GHZ Intel CPU, 1 hard drive and a pair of proprietary digital signal processor boards in it. It’s running SQL server and some proprietary DVR apps. It’s hooked to a Liebert PSA650MT-120 [this guys here]: > **[Amazon.com: LIEBERT Corp PSA650MT-120 Powersure Psa 650VA/390W 5 Min-Full...](https://www.amazon.com/PSA650MT-120-Powersure-Min-full-6OUTLETS-Minitower/dp/B0006TZINO)** > > The Liebert PSA is a line-interactive UPS that offers full-featured power protection for PCs, network workstations, small routers, bridges and hubs, point-of-sale systems and other electronic equipment. It features automatic voltage regulation (AVR),... The Liebert Multilink Viewer is showing the following: Battery Capacity 100% Battery time remaining 40 min Output load 17% Output voltage 121V I’m not quite sure how this jazz all gets calculated. Are those sane numbers? I’m asking because I’ve got similar units with show 24 minutes of battery time remaining. Anyone have any clues for me? Are there any good calculators out there for this stuff? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 23, 2009, 11:59pm UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/2 "2009-02-23T23:59:55Z")
Can you gracefully shut the machine down in 40 minutes? Seems like plenty of time to me… ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [February 24, 2009, 12:01am UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/3 "2009-02-24T00:01:58Z")
Actually, this one takes about 6 seconds most of the time, 5 minutes in rare cases. I was just worried that maybe this wasn’t my machine plugged in, just the monitor… It’s a remote machine, and my nearest staff to check out the unit is over and hour from it. ---
**Author:** ![DudleyGarrett](https://avatars.discourse-cdn.com/v4/letter/d/d9b06d/32.png) [@DudleyGarrett](https://boards.straightdope.com/u/DudleyGarrett)\ **Post date:** [February 24, 2009, 12:13am UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/4 "2009-02-24T00:13:55Z")
Via the Liebert MLV, can you see what outlets on the UPS are currently active and supplying power? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [February 24, 2009, 12:15am UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/5 "2009-02-24T00:15:21Z")
Yes, that power (17% x 390W = 66W) does seem too low for both a computer and a monitor. ---
**Author:** ![Bartman](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@Bartman](https://boards.straightdope.com/u/Bartman)\ **Post date:** [February 24, 2009, 12:45am UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/6 "2009-02-24T00:45:21Z")
> [@beowulff](#): > > Yes, that power (17% x 390W = 66W) does seem too low for both a computer and a monitor. Yeah that seems a low to me too. For comparison here is a list of PC class Dells from a few years ago: Dimension B110 (Pentium 4 520) 112W max 60W min Optiplex GX620 (Pentium 4 630) 127W max 72W min Dimension E310 (Pentium 4, 2.8GHz) 132W max 71min Optiplex 170L (Pentium 4, 3.2GHz) 163W max 80W min Dimension E510 (Pentium 4 551) 165W max 106W min Dimension XPS 600 200W max 142W min Dimension XPS 400 (Pentium 4 551) 258W max 149W min My guess is most current computers are pulling about 150W in an idle and around 300W and up at full throttle. Most monitors will pull in the range of 30W-60W. Now there are some Energy Star PCs that can be in the range of 20W-30W but you would likely know if you had one of them… they make a big deal about it, being their primary selling point. ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [February 24, 2009, 2:06am UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/7 "2009-02-24T02:06:45Z")
> [@DudleyGarrett](#): > > Via the Liebert MLV, can you see what outlets on the UPS are currently active and supplying power? Not so far as I can tell. ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [February 24, 2009, 2:09am UTC](https://boards.straightdope.com/t/is-this-a-reasonable-load-for-a-pc-with-a-ups/487125/8 "2009-02-24T02:09:23Z")
> [@beowulff](#): > > Yes, that power (17% x 390W = 66W) does seem too low for both a computer and a monitor. Ah. The spec for this product, being used as a commercial security DVR, is that the UPS is to be used solely for the computer. We don’t sell a monitor with it, but if the customer purchases the optional monitor, the directions disallow connecting the monitor to the UPS.