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1000W or 850W

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a b ) Power supply
October 17, 2009 10:33:40 PM

Just a quickie:

I'm set on the Corsair HX series of PSUs. I'm just checking how meaty to go.

System spec will be:

i7 920 D0 clocked to 4GHz (anticipating vcore around 1.35v)
Asus P6TD Deluxe
12GB Ballistix Tracer 1600MHz (already at the 1.65v threshold so any tweaks will be within stock voltage)
2x GTX285 1GB (Asus models at stock reference speeds, unlikely to overclock them)
Asus Xonar DX sound card (doesn't require additional power)
2x Corsair Extreme X64 SSDs
2x Samsung Spinpoint F3 HDDs
LG 8x BD-RW
LG 8x BD-ROM/DVD-RW

Other power-using bits of note:
3x 120mm Xigmatek XLF-F1253 LED fans
pair of 4cm red cathodes or 30cm red LED strip
some kind of overly fancy touch fan controller (Aerocool Touch 2000 for instance)


According to the eXtreme Power Calculator, the above system (with a few conservative additions like higher vcore, 100% TDP and 100% load) puts the system draw at 790W. 85% TDP and 90% load come out at 670W.

To be safe and give me some headroom with future upgrades (GTX300s, i9, etc.) and to allow for the PSU getting old (I usually get at least 7 years out of my systems) I was going for the 1000W PSU.

I know I'm not going to hit 100% TDP and load unless I'm benching or stress-testing, but am I being overly cautious with the 1000W or can I get away with the 850W and save a few quid? The 1000W is within the budget I've laid out, but saving money is good!

Your thoughts please.

More about : 1000w 850w

October 17, 2009 11:55:35 PM

the corsair hx850 is nothing compared to the xfx black edition 850. The xfx is pure 1337, it has max 30~mv ripple however i don't know if it's sold in the uk though :(  (DO NOT BUY GTX285, GET 5850/5870, 5850 = CHEAPER AND SAME PERFORMACE MOST OF TIME OR MORE BY 5% MAX)
October 18, 2009 12:09:03 AM

The Corsair HX850 is amazing. It's among the lowest ripple and best power supplies on the market. ubernoobie - Corsair is among the best on the market, and if you look at the JonnyGuru review of the XFX, he said it was comparable in ripple to the HX850. Both score the same in the reviews, and both are excellent choices. I'd tend to lean towards the Corsair, since it has been on the market a bit longer and won't blind you from a day-glo fan, but either would be a great choice.

Oh, and you don't need a 1000W supply. You could get one if you wanted, but the high quality 850s like the XFX or Corsair HX850 would definitely be good enough.
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a b ) Power supply
October 18, 2009 12:16:55 AM

Looking at the numbers on paper I don't need a 1000W but as you start adding capacitor ageing to the calculations things do start jumping up, but I'm just overly cautious.

I'll take a look at the XFX model, but I've been set on Corsair PSUs for a while now so it was just really another brain to confirm the numbers for me.

ubernoobie: I'm primarily a media creator and while I enjoy gaming I don't buy kit purely for it. So given that the majority of my media tools utilise CUDA, there's no Radeons going into this system.

By the time I get budget and everything together there may well be GTX300-series going in. Of course, if Adobe and their ilk release/update their software to use ATI's stream processors then Radeons may well be an option.
a b ) Power supply
October 18, 2009 12:20:43 AM

oh and cjl there's gonna be plenty of lighting in this bugger, but my designer side will come out and it's gonna be tasteful and sweet :-P

gonna be a fire-themed Silverstone Raven ;-)
October 18, 2009 1:54:53 AM

Go with the 850HX for the 7 year warranty vs. the Corsair 1000HX has 5 years.
a c 134 ) Power supply
October 18, 2009 3:17:11 AM

LePhuronn said:
I know I'm not going to hit 100% TDP and load unless I'm benching or stress-testing, but am I being overly cautious with the 1000W or can I get away with the 850W and save a few quid? The 1000W is within the budget I've laid out, but saving money is good!


Don't forget to account for capacitor aging (25% recommended)

Try this tool ..... http://www.antec.outervision.com/

Using the above I take my answer at 85% TDP and 90% load, 25% capacitor aging and then multiply by 1.5. And don't forget case fans (now and future) as well as connected USB and fire wire items

If using nVidia cards, then I'd make sure it's on the certified list for warranty purposes.

http://www.slizone.com/object/slizone_build_psu.html

Be wary of "fancy" fan controllers.....the NZXT looks cool for example but is a huge headache .... loses settings, fan wattage capability very low, can't handle fans w/ molex connectors, etc whereas the NZXT Sentry 2 eliminates all those problems.
a c 139 ) Power supply
October 18, 2009 3:41:38 AM

JackNaylorPE said:
..... 25% capacitor aging and then multiply by 1.5.
25% isn't a bad suggestion for older style electrolytic (wet) capacitors. But for high end polymer caps? Probably overkill - the PSU calculators aren't recommending any aging factor for the high end polymer capacitor PSUs.
If you're already adding 25% capacitor aging why are you recommending an additional 50%? The PSU calculators are already padding the actual requirement and you're adding more on top, twice.
a c 248 ) Power supply
October 18, 2009 5:33:31 AM

^5 +1 what cjl and WR2 said.

Those power requirement calculators are overestimated just like most of the manufacturer recommendations because people insist on buying cheap power supplies of questionable performance and quality.
a c 139 ) Power supply
October 18, 2009 6:14:00 AM

LePhuronn said:
According to the eXtreme Power Calculator, the above system (with a few conservative additions like higher vcore, 100% TDP and 100% load) puts the system draw at 790W.
Actually the PSU Calculator is giving you the recommend PSU wattage and not the actual DC draw of the system.



If the eXtreme Power Calculator is recommending a 670W PSU the actual draw of your components is going to be significantly under that.
October 18, 2009 7:05:11 AM

ubernoobie said:
the corsair hx850 is nothing compared to the xfx black edition 850. The xfx is pure 1337, it has max 30~mv ripple however i don't know if it's sold in the uk though :(  (DO NOT BUY GTX285, GET 5850/5870, 5850 = CHEAPER AND SAME PERFORMACE MOST OF TIME OR MORE BY 5% MAX)


The Corsair, XFX and PCP&C are all in the same range in performance. As well they should be, as they are all basically variants of the Seasonic M12D platform....

So why not cut out the middleman and get the Seasonic SS-850HT?
a b ) Power supply
October 18, 2009 12:41:10 PM

Thanks for the additional comments:

JackNaylorPE and WR2:
"to allow for my PSU getting old" was me saying I've put in 25% capacitor ageing without actually saying it - I'm such a dumbass lol - cheers for thinking of it anyway. The value came out around around 900W, hence my consideration of a 1000W unit. But as WR2 says dealing with a modern, high-quality unit I don't think it will be an issue within this system's primary lifetime.

Plus if the calculator's figures are padding anyway to begin with then there's even more of a buffer.

JackNaylorPE:
The fancy fan controller was an afterthought simply because I saw a NZXT Sentry LX in a Raven and it looked hot. I've done a fair amount of looking around for controllers and the few I'm considering have good reviews and will suit my purposes.

To be honest I'm not 100% sure I'll need it given that I'll be running the Raven's fans at full tilt because they're practically silent even at max, and a 4GHz OC will more than likely need the cooler fans at max too. Besides, compared to the wind tunnel monster I'm using at the moment I can live with a couple of 120mm fans at full - the fan controller's only going to come into play when I start experimenting with overclocking profiles and may need to dial the cooler down a bit.

croc:
Can't get Seasonic SS in the UK, but it's good to know.
a c 243 ) Power supply
October 18, 2009 1:18:10 PM

croc said:
The Corsair, XFX and PCP&C are all in the same range in performance. As well they should be, as they are all basically variants of the Seasonic M12D platform....

So why not cut out the middleman and get the Seasonic SS-850HT?

The Corsair HX 850 is built on a CWT platform, not that that takes anything away from it.

Oh, and the XFX 850 seems to have an issue,
http://www.overclock3d.net/reviews.php?/power_supply/xf...
a c 134 ) Power supply
October 18, 2009 2:53:18 PM

WR2 said:
25% isn't a bad suggestion for older style electrolytic (wet) capacitors. But for high end polymer caps? Probably overkill - the PSU calculators aren't recommending any aging factor for the high end polymer capacitor PSUs. If you're already adding 25% capacitor aging why are you recommending an additional 50%? The PSU calculators are already padding the actual requirement and you're adding more on top, twice.


Couple of reasons:

1. PSU's don't operate efficiently at full load. They generally hit their peak efficiency about 3/4 load. So having a good rated power / peak power ratio saves a bit of "juice" and $$. A 600W PSU gets pushed to 800 (1.33 multiplier) on that factor alone.

2. Inefficiency not only costs money, that inefficiency also produces extra heat

3. If ya check the SLI certified listings on the nVidia web sites, and compare their certified lists against what the calculators give you, you will always see that where they have certified an 750, your calculating 500ish. Every combination I have ever tried, checking against the certified for SLI lists always had me somewhere close to 1.50

4. The more strain you put on a PSU, the harder it is for it to maintain stable voltages. If you are OC'ing, that gets kinda important.

5. The 1.5 is for 2 or 3 GFX cards and hard OC'ing.....would use lower numbers as the harshness of the demand drops.

6. If keeping a box for 4 or more years,. do we know today what will be connected to it in 3 years ....when granny sends you a web cam... you add a card reader, camera, fan controller, extra HD's, external HD's or other items you didn't anticipate, that's extra load.

7. Into quiet ? Where do you want your fan operating .... at 100% or a lesser number ? Bigger PSU's are designed with expanded cooling capabilities....a 550 watt PSU at 500 watt draw is screaming. A650 not so much, an 850 is a bit above ambient at worst.
a b ) Power supply
October 18, 2009 3:01:41 PM

So your call is for the 1000W then Jack

let's do a show of hands!

Who's for the 1000W, who's for the 850W?
a c 134 ) Power supply
October 18, 2009 3:03:07 PM

LePhuronn said:
The fancy fan controller was an afterthought simply because I saw a NZXT Sentry LX in a Raven and it looked hot. I've done a fair amount of looking around for controllers and the few I'm considering have good reviews and will suit my purposes.


Yeah, had same initial reaction until I read reviews on newegg of the LX.....not the company as the Sentry 2 is a damn good one though woulda like a bit more rigidity in the construction. If ya bump up from the P6T to the Rampage II Extreme, ya can use the Asus OC Station. I smirked a bit when my son said he wanted it but it's a fine fan controller albeit a bit expensive at $149 to control fans. But it also lets you OC your PC (except memory) from the front panel w/o rebooting and going into the BIOS so that's worth a few bucks....thou to my mind, I'd say $99 is an appropriate price for fan control and OC'ing.

But then again, ther eis the bling factor and, hey, the kid is paying his own tuition, had stayed within his budget for his PC Build, I couldn't resist letting him have a little "bling" :) 
a c 139 ) Power supply
October 18, 2009 4:49:25 PM

JackNaylorPE said:
1. PSU's don't operate efficiently at full load. They generally hit their peak efficiency about 3/4 load.
PSUs can operate efficiently at full load, just not at the best possible efficiency. And the drop off isn't huge on a high quality PSU. A quality PSU like the Corsair 850HX will hit 89% at typical load and 86% at full load. The 850HX efficiency is higher at full load than the 1000HX's best efficiency (85%). You could save more money on the initial cost AND save an extra buck or two each year with the more efficient PSU. I think the PSU calculator pads the PSU recommendation along the lines of your 3/4 load target.
2. Inefficiency is relative. Again, 850HX is more efficient at full load than 1000HX at 50% load. 850HX should save money, up front, and over time and generate less heat than 1000HX. Although the prices are surprisingly close.
950TX vs 1000HX is much wider price gap. Also the 950TX looks 84% efficient at full load over the 1000HX's 85% best efficiency. If saving money is an objective going with a larger than necessary PSU isn't helping.
3. nVidia covering their collective posteriors.
4. Not true of high quality PSUs that stay in spec right up to full load even under hotter than normal testing. (thanks JonnyGuru)
5. The PSU calculators handle CPU overclocking OK IMO, but aren't set up for GPU overclocking or Tri or Quad GPUs.
The only time I think a 1.5 factor is called for on a regular basis is when tight finances require a person to go with a less than stellar make and model.
6. It's unlikely that all the extra goodies are drawing full power at the same time, and if they are in use will the rest of the system be fully loaded?
7. A 1000HX is louder at every load than 850HX at the same load point. Including 850W.
Thanks to the Corsair website for all the pretty charts.

a b ) Power supply
October 18, 2009 7:27:19 PM

JackNaylorPE said:
If ya bump up from the P6T to the Rampage II Extreme, ya can use the Asus OC Station.


This was my first choice, but I forget now why I moved to a P6T Deluxe v2. That board in turn has been superseded by the P6TD Deluxe which is basically the same board but using Asus new Xtreme Design which has a number of funky new features like cooling improvements and newer versions of the overclocking software (Turbo V) found with the Republic Of Gamers stuff.

The only thing I would consider the Rampge II for is Tri-SLI, but to be entirely honest I'm not enough of a gamer to go that far, and I'd probably get the EVGA X58 Classified for that anyway.
a c 248 ) Power supply
October 18, 2009 11:47:19 PM

GEEZ! Is everybody getting carried away with psu wattage? What did I miss?

The general rule of thumb is a high quality 500 to 550 watt power supply with sufficient current (amps) on the 12 volt rail(s) can easily power a system with any single video card made. A high quality 700 to 750 watt power supply with sufficient current (amps) on the 12 volt rail(s) can power a system with two video cards operating in dual mode. There are a few exceptions like the new ATI Radeon HD 5XXX series cards which use less power due to their energy efficiency.

LePhuronn - In your original post you only mention two GTX285 video cards. Here is a link to a very good technical review of GTX285 video cards. Take a look at the power consumption section:

http://www.guru3d.com/article/geforce-gtx-285-review--3...

Bear in mind that it is the power consumption of the entire Intel Core i7 965 / X58 based system.
a b ) Power supply
October 18, 2009 11:56:25 PM

JohnnyLucky said:
GEEZ! Is everybody getting carried away with psu wattage? What did I miss?


Well I was wondering when you were gonna show up again ;) 

JohnnyLucky said:
Bear in mind that it is the power consumption of the entire Intel Core i7 965 / X58 based system.


556W for the lot??? The 850HX is it then!
a c 248 ) Power supply
October 19, 2009 12:20:20 AM

It's a National Football League game day in the USA. One more game tonight. :bounce: 
!