power consumption and UPS advice...

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Lykho

253 posts

Ultimate Geek

#90870 1-Oct-2011 16:09

after about the sixth power loss to my rather new computer (...yay, Christchurch), I'm considering buying a UPS.

is there somewhere I can go in Win7 to see what the power consumption of my PC is? (since I might be pushing the limits of the loading capacity of certain UPSs I'd like to know exactly how much it uses, rather than having some rough '100-150w' estimate.--I'd hate to get a UPS with a 200w instead of a 300w+ limit, and find out that my PC actually uses way more than expected.)

is there a way to find out without any special tools? (I know I can google the power consumption for my monitor, but to figure out what all the PC components would end up using? I have no idea)

also, any brands or stores I should definitely avoid?

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#528035 1-Oct-2011 16:28

Not that i've found. There are tools that will show you what power load your UPS is under (If connected via USB)

Don't forget you need to factor in how much power your (at least one) monitor uses!

Look on the back, it should show current/voltage. (In this case voltage is usually ~240). So if you monitor uses 1Amp, the wattage will be 1*240=240W.
You should be able to open your PC and check what wattage PSU you have, but realistically most PC's don't use that much. I have a Core i5-2500k OCed to 4.3ghz, a radeon 6870, 8GB RAM, an SSD and a 1TB HDD + a 24" monitor and it never went above 300W usage on my UPS, even maxed out.
Certainly go for overkill rather than being cheap. APC is a decent brand PSU.

If you get a higher specced UPS than you need, you'll just get better run time on battery :)

gregmcc

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#528041 1-Oct-2011 16:50

kyhwana2: Not that i've found. There are tools that will show you what power load your UPS is under (If connected via USB)

Don't forget you need to factor in how much power your (at least one) monitor uses!

Look on the back, it should show current/voltage. (In this case voltage is usually ~240). So if you monitor uses 1Amp, the wattage will be 1*240=240W.
You should be able to open your PC and check what wattage PSU you have, but realistically most PC's don't use that much. I have a Core i5-2500k OCed to 4.3ghz, a radeon 6870, 8GB RAM, an SSD and a 1TB HDD + a 24" monitor and it never went above 300W usage on my UPS, even maxed out.
Certainly go for overkill rather than being cheap. APC is a decent brand PSU.

If you get a higher specced UPS than you need, you'll just get better run time on battery :)

Very basic calculation, this doesn't take in to account the Power Factor due to both of them using switchmode power supplies. Noticed that UPS are rated in VA or KVA, thats volt x amps.

Without using some power monitering equipnment a good saftey margin would be a 0.75

When you buy a UPS don't shortchange yourself on the size of it, make it big enough to look after your dsl modem/speaker amp/printer, so all of your computer equipnment is protected.

Don't forget unless you buy a super expensive UPS you will need to on a regular basis run the batteries flat to keep them conditioned.

kyhwana2

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#528042 1-Oct-2011 16:52

Oh yes, make sure you plug your modem/router/switch/anything else plugged into your computer or needed to run your network ;)

Niel

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#528065 1-Oct-2011 19:16

Typically a $100 - $150 consumer UPS will keep a PC and monitor running for 10 to 15 minutes and has a connection to the PC for monitoring and to perform shut-down when the batteries run low. If you want anything more than that you will pay $500+.

A number of years ago I've installed a UPS for my in-laws and that same evening they had a power outage. We were confused for a while, because the PC monitor was lighting up the living room but the TV and all the lights were off. Then we remembered the UPS...

You can never have enough Volvos!

Lykho

253 posts

Ultimate Geek

#528091 1-Oct-2011 22:32

kyhwana2:
Don't forget you need to factor in how much power your (at least one) monitor uses!

the company website says "29W (typ)"

kyhwana2:
Look on the back, it should show current/voltage. (In this case voltage is usually ~240). So if you monitor uses 1Amp, the wattage will be 1*240=240W.
You should be able to open your PC and check what wattage PSU you have, but realistically most PC's don't use that much. I have a Core i5-2500k OCed to 4.3ghz, a radeon 6870, 8GB RAM, an SSD and a 1TB HDD + a 24" monitor and it never went above 300W usage on my UPS, even maxed out.
Certainly go for overkill rather than being cheap. APC is a decent brand PSU.

::blink::

gregmcc:
Very basic calculation, this doesn't take in to account the Power Factor due to both of them using switchmode power supplies. Noticed that UPS are rated in VA or KVA, thats volt x amps.

::blink:: ::blink::

aaaaaaaaaaah. suuuuuuurely my monitor won't use up 240W!! some UPS's barely offer 300W! (then again, a 100w lightbulb uses 100w, right? ::scratches head::)

kyhwana2, are you saying your monitor used a solid 5-times more power than the rest of the PC? (240 out of less than 300)

this page seems to suggest that monitors shouldn't use more than 50
and this one that a mere processor can use about 30.
picking roughly what my specs are, this site says 200w minimum 250w recommended (excluding monitor)

Skolink

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#528113 1-Oct-2011 23:27

You can get a cheap power monitor from a few places, I got one like this from Bunnings for $20
http://www.jaycar.co.nz/productView.asp?ID=MS6115&keywords=MS6115&form=KEYWORD

I'm not how accurate is is for non-linear loads (they don't draw nice sinusoidal current), but my PC (with a "300W" power supply uses 70W when idle and around 95W when under load (I don't think that was gaming, just the CPU under load).

timmmay

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#528140 2-Oct-2011 00:58

My Q6600 PC uses 15W when off, 70W when idle, 110W under load. That doesn't count monitor, router, or modem. When the power's out TelstraClear cable fails anyway, apparently their repeaters need mains power, so doesn't much matter if the PC works or now.

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Lykho

253 posts

Ultimate Geek

#594698 13-Mar-2012 18:13

Skolink: You can get a cheap power monitor from a few places, I got one like this from Bunnings for $20
http://www.jaycar.co.nz/productView.asp?ID=MS6115&keywords=MS6115&form=KEYWORD

I'm not how accurate is is for non-linear loads (they don't draw nice sinusoidal current), but my PC (with a "300W" power supply uses 70W when idle and around 95W when under load (I don't think that was gaming, just the CPU under load).

]

so, I've finally gotten around to buying a power meter. looks like 95w idle/in use, spiking to 140w at most when booting up or shutting down.

the last question I have, then, is this:

apparently it's a 1:1 conversion between VA and Watts. However, some web results suggesting that this may be a conservative/rough number.
from the first page of google results, you see things like:
"400Va 279 Watts"
"240 Watts / 400 VA"
"400VA 210 Watts"

is this something to do with 'power factor' (the meaning of which I don't comprehend) or something?

gregmcc

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#594705 13-Mar-2012 18:29

Lykho:
Skolink: You can get a cheap power monitor from a few places, I got one like this from Bunnings for $20
http://www.jaycar.co.nz/productView.asp?ID=MS6115&keywords=MS6115&form=KEYWORD

I'm not how accurate is is for non-linear loads (they don't draw nice sinusoidal current), but my PC (with a "300W" power supply uses 70W when idle and around 95W when under load (I don't think that was gaming, just the CPU under load).
]

so, I've finally gotten around to buying a power meter. looks like 95w idle/in use, spiking to 140w at most when booting up or shutting down.

the last question I have, then, is this:

apparently it's a 1:1 conversion between VA and Watts. However, some web results suggesting that this may be a conservative/rough number.
from the first page of google results, you see things like:
"400Va 279 Watts"
"240 Watts / 400 VA"
"400VA 210 Watts"

is this something to do with 'power factor' (the meaning of which I don't comprehend) or something?

That is power factor.

Watts is a measure at the rms value of the voltage x amps at the exactly same time, where as VA or KVA is the tms voltage x the max amps, the max amps when it is not achived at the same time as the rms voltage is the power factor difference, a resistive load (such as a heater) will have a power factor or 1, and inductive load, such as a motor or switchmode PSU has a power factor of <1

that's the simplified version .

Lykho

253 posts

Ultimate Geek

#594708 13-Mar-2012 18:35

gregmcc:
that's the simplified version .

::blink::

is it something I need to understand? (looks like I'll never load near whatever the actual capacity is.)

gregmcc

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#594709 13-Mar-2012 18:42

Lykho:
gregmcc:
that's the simplified version .

::blink::

is it something I need to understand? (looks like I'll never load near whatever the actual capacity is.)

No you really don't need to know all the in's and out's of power factor, when you are buying a UPS, buy a good brand, over estimate what size you think you need.

Greg

robertcnz

8 posts

Wannabe Geek

#594720 13-Mar-2012 19:12

Get a Double-conversion / online one if you can. Used all three common types now and found that I have less problems with this type instead of the others.

Wiki definition : -

http://en.wikipedia.org/wiki/Uninterruptible_power_supply

Rgds

cyril7

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#594744 13-Mar-2012 20:35

Hi, the most basic UPS you would need is one of these (see 6th device on page below UPS650 with USB interface) this will easily support what you want and your modem etc etc.

We supply these as basic units to client with one or two basic servers.

http://www.cablesdirect.co.nz/catalog/entry?entry=163

Cyril

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#594824 13-Mar-2012 22:20

cyril7: Hi, the most basic UPS you would need is one of these (see 6th device on page below UPS650 with USB interface) this will easily support what you want and your modem etc etc.

We supply these as basic units to client with one or two basic servers.

http://www.cablesdirect.co.nz/catalog/entry?entry=163

Cyril

That is certainly affordable. What is the battery capacity?

mattRSK

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#594837 13-Mar-2012 22:33

Lykho:
gregmcc:
that's the simplified version .

::blink::

is it something I need to understand? (looks like I'll never load near whatever the actual capacity is.)

This helps me.

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