Would a 450W UPS power a 900W rig for at least 10 secs?

martinduque86

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May 10, 2011
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Hello everyone!

Quick question here: would this 450W / 750VA UPS (BE750G) power this 750W PSU (750TX V2) rig + 150W peripherals (total 900W) for at least 10 secs after power goes out? Or it wouldn't even let the rig turn on?

If not, what $ 100-ish UPS or AVR solution would you recommend? I live in a dirty power zone so at least an AVR is necessary.

Thanks in advance! :)
 
Your computers PSU does not always draw 750w, it only draws what is needed at the time so we would need a breakdown of your system to judge accurately.

Also, your current PSU likely has Active PFC (power factor correction) and therefore will not work with standard UPS's, you will need one with a true sinewave output.
 
i think you could use this instead

http://www.pcworld.com/shopping/detail/prtprdid,843786-sortby,retailer/pricing.html

it should keep the voltage at a steady level

your computer only draws the current it needs, so you dont have to worry about that

you could use a ups if you wanted to, i think a voltage regulator would be better


and if you havent got an rcd either call an electrican in or buy one of the plug in ones
 
If you are a using a regulated power supply, which I think most computer PSU's are, then a voltage stabilizer won't do much. The PSU is already stabilizing the voltage that goes to your components and is designed to deal with variations in input voltage from the outlet.

I could be mistaken, I think that computer PSU's are regulated (in terms of what I think, as in constantly stabilizing a perfect voltage). Please correct me if I am wrong.
 
I'm going to assume that at idle your PC will run for ~2 minutes, and if it is under load it will just shut off power to your PC.

This is assuming you have a properly sized PSU and it isn't just way bigger than needed. I'm also assuming that your 150W in accessories actually draws 150W (say 3 LCD monitors that are on)
 


A UPS is just a battery back up...gives a few minutes of power.

A voltage regulator stabilizes voltage...two different things. I'm just saying that you can get a UPS without voltage regulation, because your PSU should already be regulating voltage.
 
The Active PFC circuit of a PSU is actually a DC boost converter that takes any incoming voltage from 90 V to 240 V and converts it to a constant DC voltage for use inside the unit, if your power isnt dropping below 90 V or shooting above 240 V then an AVR isnt going to help.


You also cannot use a UPS that small for the system, a UPS is a battery back up that then needs to convert the power from DC back to AC, the wattage rating of a UPS is the rating of the power inverter, if you try to draw more than its rated for it will either shut itself off, or try to handle the load and die. Make sure the UPS can handle the max possible load the computer might be drawing when it shuts off, likely still not 900W but definitely more than 450 W.
 
Thanks everyone for the replies.

So far I've learned a couple of things from your posts; please correct me if I'm wrong.

PSU: Corsair's 750TX V2

1. Since my PSU has active Power Factor Correction (PFC), an AVR (the likes of APC's LE1200) wouldn't do any good since it is not actually needed; the PSU has its own voltage regulation.

2. 450W UPS (the likes of APC's BE750G) probably wouldn't suffice to power a 750W PSU (max load) + 150W in peripherals (2x LCD, eSata, 5.1 speakers, etc.); a 600W+ UPS would be required for at least 1 min of power, not to mention being able to power on the computer on startup and to handle full load without beeping or powering off.

3. Good branded UPS are expensive, not likely to get a 600W+ for less than $ 130.00 USD (even more if I could only use an UPS with true sineweave output because of the active PFC technology on the PSU).

Finally, unless I'm completely mistaken (and please tell me if I am in any way), a SURGE SUPPRESSOR is the only power protection device I would actually need (and I empathize the word need since making the new rig "fire proof" is all I really want). The surge suppressor would hold the rig itself and all of the peripherals. What do you think?

One last thing: I currently own this APC's Back-UPS RS 500. It can handle 500VA / 300W. I know this is not enough to hold the entire 900W on battery backup, probably not even to power it on... but maybe I could just plug it into the "surge only" output, using it as a standard surge suppressor (the likes of APC's P6N); please correct me if I'm wrong.

... or should I still get an AVR for the peripherals?

Again, thanks everyone for their valuable feedback!
 
The idea behind a UP is to give you time to shut down; so to do this you only run things off the UPS that might be damaged by a sudden loss of power. You printers, speakers, and disco-ball (joking) are not items you would even plug into the UPS.
Your RS500 cannot run a 900w load; but more realistically, since you still haven't listed your system specs, at its 300w maximum load and a newer battery in the UPS you will have 3 minutes to shut down.
 
Going with what popatim said, the only things I recommend plugging into your UPS is your computer and monitor. That way, if power goes out, you have time to save whatever you are working on and shut-down. If you aren't home, you aren't working on anything so it shuts it down for you.
 




HAWKE V1.1 - System Specs:

CPU: INTEL i5 2500k (BX80623I52500K)
CPU HEATSINK: COOLER MASTER Hyper 212+ (RR-B10-212P-G1)
MOBO: ASUS P8P67 Pro (REV 3.0)
RAM: G.SKILL Ripjaws 1600 (F3-12800CL8D-8GBXM)
GPU: MSI GTX 560-Ti HAWK 1gb (N560GTX-Ti Hawk)
HDD: SAMSUNG Spinpoint F3 (HD103SJ)
PSU: CORSAIR TX750 V2 (CMPSU-750TXV2)
CASE: COOLER MASTER HAF 922 (RC-922M-KKN1-GP)

Tried plugging the computer and 1x monitor into the UPS's 'battery backup' outlets. Worked fine on idle but started beeping uncontrollably while torturing the GPU. Didn't power off though...

Even if a 300W UPS on new battery could handle the system on idle as it is right now, I plan on upgrading: adding an SSD, second HDD, soundcard, maybe even a second GPU on SLI if the PSU is able to handle it. That's why I require and UPS able to handle the system on full load.

... and you're right, since I would only be plugging the computer and 1x monitor into the UPS 'battery backup' outlets, I don't really need a 900W UPS; an 800W-ish one would do the trick.

One last thing, since I don't really need half an hour of working battery once the power goes off, do you think the new APC's BX1000G 1000VA / 600W UPS could handle max possible system load (800W), and at least 1 or 2 minutes once the power goes off? I could save a little bit and buy this UPS.

Thanks for your valuable input! 😀
 
Forget the size of your PSU, Your computer is under 450 Watts (Running a game).
My I5-2500k, 6870 GPU, 16 gigs ram, 2 SSds, a HDD, a Blu-ray drive is right at 350 Watts running furmark (Under 200 Watts @ Idle). Anything over 600 ->750 Watts should give you time to shut down (Or let the UPS shut it down).

If you want more time, you can even leave the monitor off (I do not have the Monitor connect, just the computer). No monitor - Windows key, Right arror key then Enter. If it does not shut down in 1 Min then hit Y, then enter (has programs running and asking do you want to terminate programs.

Some comments.
You used the term "dirty power" which covers several conditions: Power goes out, comes back on; Brown-outs, voltage dropps then comes back up. Good ex turn the vacuum cleaner on and the lights dim then come back up; then dirty power, which is the AC with Noise spikes on it.

On " PSUs regulate voltage" Yes for example your 12 V is regulated and compensates for (A) changes in load such as changing between 2D and 3D graphics (game) and (B) Varing AC input. The problem is that the Regulator must first detect the change, then compensate for the change. Say that the AC input drops to 105 V from 120 VAC and stays there for 5 Sec then back to 120 VAC. Your +12 V will show a negative spike at the beging and 5 sec later a positive spike.
If you have problems with the AC input varing you should get an UPS that has a regulated output, not one that has a regulated output ONLY when the AC input is out - Widely varing AC (ie 95->130 VAC) is hard on Pwr supplies..
If You only have problems with power OUTAGE, then the "Switched" ups is fine.

The best UPS I ever had was one that had an regulated output all the time and "near" perfect sinewave output. $250 and back in 1990.

Added: make sure you test the UPS. If you have not had an outage for 6 months, pull the plug to test.
 


Thanks for the extremely useful information!

I gotta say, picking up a power protection device has been -by far- way more difficult and confusing than any other hardware piece on my entire system.

I ask you, would you recommend this UPS to fully protect and power my system (at least for a couple of minutes)?

APC's BX1000G 1000VA / 600W UPS

Thanks in advance!

 
My est, you should get 5->8 minutes run time if gaming, if your system is 2 Idle you should get closer to the 16 Mins (advertized 1/2 power load time). However it does not indicate how close the output waveform is to a sinewave. Most that have a "near sinewave output advertize that.

With the PFC in most computer you can ignore the VA rating.
Reason. PFC brings the Power factor closer to 1 (Resistive) and the 600 Watts is applicable. The VA rating is for loads that have a high capacitive/Inductive component. This cause max voltage and max current to be out of Phase.
 


Thanks!

Found APC's info for the BX1000G 1000VA / 600W UPS: http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BX1000G

It says 'Waveform type: Stepped approximation to a sinewave.'

Is that good enough?

Also, if so, could it handle the system if eventually I added a second GPU (getting close to the PSU's 750W max possible load + 50W monitor). Maybe keep it on for a couple of minutes at least when power goes out?

Thanks again for the valuable input! You've been very helpful. :)
 
Need your system configuration. For example I have a 6870 GPU.
Normal system w/6870 will draw about 300 Watts (That is SYSTEM) adding a 2nd 6870 would jump wattage for my computer upto arrox 450 Watts. Far short of a 750 Watts (Wattages are under LOAD, Idle is ofcourse much lower).

(1) You do not want to exceed the max wattage rating, ie 600 W.
(2) You do NOT want to run a system at 100% of PSU rating, I notnrmally us 80% as a top. .8 x 750 = 600 Watts (600 watts + monitor (50 watts) should be ok for a short 2 min time frame for a 600 Watt UPS.
(3) Get a better handle on your TRUE power consumpsion.
.... Google Your video card and look at what it says for system power, also check for sli/xfire configuration if that is what you are planning.
.... Buy a watt meter and measure your tru power consumpsion. What I use, $20 @ newegg (offten on sale for $16)
http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001
then factor in the 2nd GPU (Google review of GPU, BUT make sure it shows power consumpsion for JUST the GPU, not the System.
Here is a example using my 6870 GPU: http://www.guru3d.com/article/radeon-hd-6850-6870-crossfirex-review/4
 


HAWKE V1.1 - System Specs:

CPU: INTEL i5 2500k (BX80623I52500K)
CPU HEATSINK: COOLER MASTER Hyper 212+ (RR-B10-212P-G1)
MOBO: ASUS P8P67 Pro (REV 3.0)
RAM: G.SKILL Ripjaws 1600 (F3-12800CL8D-8GBXM)
GPU: MSI GTX 560-Ti HAWK (N560GTX-Ti Hawk)
HDD: SAMSUNG Spinpoint F3 (HD103SJ)
PSU: CORSAIR TX750 V2 (CMPSU-750TXV2)
CASE: COOLER MASTER HAF 922 (RC-922M-KKN1-GP)

That's my system configuration.

I've looked at several reviews for the MSI GTX 560-Ti HAWK (N560GTX-Ti Hawk) GPU, half of them (HardOPC, TweakTown, Overclocker's Club) say the power consumption of the GPU alone is about 20W on idle, 301W on stock load, and 342W overclocked. The other half (Benchmark Reviews, 3D Guru, Bit-Tech) say the power consumption for the GPU alone is about 36W on idle, 214W on stock load, and say nothing about overclocked. Now, that's a HUGE difference, I don't know which group to believe.

If I am to assume the average enthusiast computer (no monitor, no peripherals) consumes around 150W, and then I decide to believe the first group, then there's no chance in hell my PSU could handle 2x MSI GTX 560-Ti HAWK (N560GTX-Ti Hawk) GPU in Sli, as it would take a total of 752W to work on stock load (even more if overclocked). If I am to believe the second group instead, then my PSU would be able to handle stock load Sli at 578W. Which one would you believe?

[strike]Also, what do you say: is the 'Waveform type: Stepped approximation to a sinewave.' good enough? or do I need pure sinewave for a UPS?[/strike]

EDIT: Just found out that 'Waveform type: Stepped approximation to a sinewave.' is not compatible with PFC. Have my eyes set on this 'pure sinewave' UPS: CYBERPOWER CP1000PFCLCD 1000VA / 600W (CP1000PFCLCD)http://www.newegg.com/Product/Product.aspx?Item=N82E16842102132. What do you think of it?


Thanks in advance! :)