need help estimating power requirements

SpannerMonkey

hi guys could anyone estimate the power requirements for the following spec computer

computer spec is

Intel 17 3770k overclocked to 4.6Ghz
Asus Gtx 670 Direct CUII Top x 2
Z77 Sabertooth Motherboard
ASUS xonar essence STX soundcard
16 GB Corsair vengance LP RAM
Be Quiet Dark Rock Pro 2 Cpu cooler
stock fans on a Coolermaster Cosmos 2 ( approx 7 fans)
256GB Samsung 830 SSD
1Tb velociraptor HDD
Asus BW-12B1LT Optical drive
backlit keyboard
headset

Serephucus

GTX 670 SLI pulls in the neighbourhood of 600W from the wall (which equates to 510W through the PSU) under gaming load, so I'd go with a good 650W unit to be safe, and to allow for some OC headroom. Something like this.

SpannerMonkey

thanks serephucus its actually for a UPS system i was asking the question , would i still need a ups rated to 650watts ?

Serephucus

Ah, well that's a little different. With a UPS you need to factor in the efficiency of the PSU, as the UPS basically takes the place of the wall. What PSU do you have powering all that?

SpannerMonkey

Seasonic 1000W Platinum , wanted something i could upgrade with .its supposed to be very high eficiency

http://www.seasonicusa.com/Platinum_Series.htm

Serephucus

Alright, so my figure of 85% was actually worst-case for that PSU (heh, gotta love Platinum efficiency) so that would mean you'd want probably a 1000VA unit to be safe.

SpannerMonkey

spot on thanks for that info Serephucus

ok just looking at a few UPS and came across someone saying that most ups are not suitable for PSU's wth active PFC (which most hight end psu's have)
something about needing a true sine wave and not a stepped

anyone know anything about this ?

Serephucus

Different implementations of alternating current.

SpannerMonkey

so does that mean i need a ups that has a true sinewave output ?

Serephucus

You do, yeah. A PSU with APFC will not function when given a stepped sine wave.

SpannerMonkey

summit like this ? http://www.overclockers.co.uk/showproduct.php?prodid=UP-016-CY&groupid=701&catid=123&subcat=2108

Serephucus

Looks good to me. I don't know much about UPSs though, I'd read reviews, do research, etc. to be sure.