Power Supplies

deconduo

I've noticed a lot of misinformation being spread about power supplies, so I'm going to try and give a quick run through of what you need and don't need.

First of all, here are some useful links:
http://www.tomshardware.com/reviews/geforce-radeon-power,2122.html
http://www.jonnyguru.com/modules.php?name=NDFAQs

One of the most important properties of a PSU is the 12V rail, more so than its rated Wattage. In essence, this is the 'true' wattage of the PSU as most modern components will be drawing their power for their, especially the Graphics card. Using Power = Current X Voltage you can work out how much current should be specified for the 12V Rail. For example, a 500W PSU with 25A on the 12V Rail is essentially only a 25x12= 300W PSU. Most good quality PSUs will have at least 90% of their rated output on the 12V rail.

So how much power do you actually need for a system? Well for a typical system with 2 RAM modules, a single mechanical HD, a DVD drive and a few case fans you are looking at roughly 40-60W excluding the CPU and GPU.

For the CPU under maximum load:
Phenom II X4 @ 4GHz ~140W
i5-2500k @ 4.5GHz ~ 100W
i5-2500 ~ 60W

For GPUs it varies wildly, so look a review at xbitlabs.com to get an idea.

Where does that leave us? Well for an i5-2500k OC + 560Ti for example, it leaves you at 60W (System) + 100W (CPU) + 160W (GPU) = 320W. Now, a PSU operates best when its between 65% and 85% of its full load. For example, a good 450W PSU would be operating at ~70% under the largest load that this system could pull.

Here's where some of the misinformation pops up:

Dublin_Gunner wrote: »

The entire decent PC will consume around 350W, so factoring in 80% efficiency as a rough figure, requires around a 450W PSU at LEAST.

This is not how efficiency works. Yes, if you measured the power draw from the socket of the computer you would see 450W being drawn. HOWEVER PSUs are rated for what they can supply to the computer, not for what they draw from the socket. A 350W PSU can draw 440W and still function fine, in fact thats what its supposed to do.

As a quick reference, this chart is useful:
http://images.anandtech.com/graphs/graph4239/36072.png

This is the full system power consumption. Ideally you would want a PSU that would put the PSU at ~75% load, so multiply the figures there by 1.25 to get an idea of what sort of PSU you want.

Good PSUs to look out for would be:

Antec Earthwatts
Antec TruePower
Seasonic S12II
Seasonic X
Corsair TX
Corsair VX
Corsair HX
XFX Core Pro
SuperFlower Amazon
SuperFlower Golden Green

There are a few others, but thats a pretty good start.

Solitaire

The load level you should shoot for is 50% of the total 12V output. What constitutes load is a bit trickier - especially for gaming systems. You need to research high-to-maximum power consumption at your desired clock speed (OCing consumes some extra power, overvolting as well consumes a lot more power!) for your current/desired CPU and all GPUs. Don't use results derived from Crysis or torture tests like OCCT/Perestroika, FurMark or IBT/Linpack to provide the "average load" figure for this as they can actually drive hardware past normal thermal specs and we're not looking for worst-case figures here. The latest 3DMark with some lower-priority protein folding in the background to eat spare CPU cycles gives "normal" gaming consumption with a slightly-pessimistic CPU power spec and is what a gaming system needs to match to the 50% mark. Then so long as the above torture tests pass below the 90% mark (hugely unlikely) you're golden. Crysis may gobble juice but it isn't the only game you play so don't sweat it if reviews suggest it would push you to the 60-70% mark. Folders need to pay attention to the CPU power usage a bit more than other gamers as few games push the CPU to 100% consistently let alone breaking point; OCCT on the other hand just isn't normal usage.

Unless you have a Gigabyte Odin GT you have to get all those figures off the web to boot Xbit Labs is the best; I've been able to confirm their findings with my Odin's integrated DVMs. There are other resources out there but they tend to be less accurate or contradict themselves at times.

Multi-rail PSUs are not the work of the Devil. Don't let flim-flammery confuse you about that. The only time there's an issue is if you tried to run a HDD-heavy server on an older multi-rail PSU that tries to lump all system power from fans and drives, the mobo, the first 75W of each GPU and most and sometimes even all the CPU consumption on just one ~200W rail. Then when the HDDs all spun up together at startup you could trip the OCP and crash out before the OS finished booting

Superflower (and the NZXT and KingWin rebadges) are on top form. Their Gold and Platinum units are still very pricey AFAIK, but they're the best on the market.

At the moment the most contentious niche is the low end gaming-grade, as it is hugely 12V-based and some awful PSUs from otherwise-reputable names have been doing the rounds, based on late Pentium 3 (i.e. 5V-based) designs with a reinforced 12V rail. The small 3.3V/5V load on such systems is insufficient to keep the 12V rail at 12V, or even 11V while gaming! :eek:

The revamped Cougar A-series are good budget units AFAIK, the 350W and 400W units actually look to be underrated!

The Corsair CX500/600 are also decent enough for the price AFAIK, its only the CX430 which sucks in a truly astonishingly vile way

IIRC most of the more powerful Coolermaster units are decent, but don't touch GX/HX units or older ones under 700W with a bargepole.

be quiet! and Antec's Basiq units are average, but will do in a pinch.

Avoid the really cheap basic Superflower units - only get the Amazon units or better. Avoid Jersey/RaidMax/ChiefTec/DiabloTek/Xilence and most Xigmatek PSUs like the plague! Avoid anything under €30 like it has freakin' Ebola! :eek:

darego

what do you think about xfx psus solitaire mate? i got this 750 watt
http://www2.hardwareversand.de/articledetail.jsp?aid=42451&agid=1630

for this system from hws on friday
http://www.speedyshare.com/files/28480708/pc.JPG

Static Jak

I'm getting my GTX 560 in a few days. My PSU (Module) has 2 places for 6 Pin PCI-E Power Connections (another two for 8 pin aswell) that I should be able to connect to the card.
Except I don't have the two cables. I have looked everywhere at this point and can't find them. I've hit a brick wall at this point.
Any ideas where I could find 2 at this point?

deconduo

@darego

Yes thats a really good PSU and great value for money. It will let you SLI your 560 Ti as well in the future.

Static Jak wrote: »

I'm getting my GTX 560 in a few days. My PSU (Module) has 2 places for 6 Pin PCI-E Power Connections (another two for 8 pin aswell) that I should be able to connect to the card.
Except I don't have the two cables. I have looked everywhere at this point and can't find them. I've hit a brick wall at this point.
Any ideas where I could find 2 at this point?

Do you mean its a modular PSU and you don't have the cables? Or that you need a PCI-E to Molex connector? What model PSU is it?

Static Jak

deconduo wrote: »

@darego

Yes thats a really good PSU and great value for money. It will let you SLI your 560 Ti as well in the future.



Do you mean its a modular PSU and you don't have the cables? Or that you need a PCI-E to Molex connector? What model PSU is it?

That my PSU is modular and I don't have the cables.

The PCI-E to Molex are the usual ones that come with the Cards right? I believe the card will have two with it. From what I've seen anyway.

The PSU is an EVO 700watt Micro ATX.

deconduo

Unfortunately the modular cables are usually unique to each model, or at least each brand. That PSU doesn't look great though, £20 for a 700W PSU doesn't inspire me with confidence.

Is it this one:
http://www.envizage.com/products/power-supplies-evo-labs/psevo-700w-12cm-evo-labs-700w-atx-silent-pc-power-supply-unit.html

Static Jak

deconduo wrote: »

Unfortunately the modular cables are usually unique to each model, or at least each brand. That PSU doesn't look great though, £20 for a 700W PSU doesn't inspire me with confidence.

Is it this one:
http://www.envizage.com/products/power-supplies-evo-labs/psevo-700w-12cm-evo-labs-700w-atx-silent-pc-power-supply-unit.html

Nah, that definitely isn't it.
So, any ideas outside of having to buy a new PSU?

marco_polo

This is amusing read, tomshardware bought 1670W worth of power suplies (three altogether) for $60, burning up the 750W one at 50% load.

http://www.tomshardware.com/reviews/low-cost-psu-pc-power-supply,2862.html

Monotype

PSU maker and model list showing OEMs.

http://www.tomshardware.com/reviews/power-supply-oem-manufacturer,2913-4.html

Solitaire

Tom's Hardware wrote:

The lowest of the low was a European label called Hardwaremania24, targeted at OEM PCs. While still in standby mode, the PSU heated to about 176 degrees Fahrenheit, spent the next six hours billowing smoke, and finally made what might be described as a trumpeting sound before dying. The host computer was never even turned on.

Komplett-Tech: Ryan

darego wrote: »

what do you think about xfx psus solitaire mate? i got this 750 watt
http://www2.hardwareversand.de/articledetail.jsp?aid=42451&agid=1630

for this system from hws on friday
http://www.speedyshare.com/files/28480708/pc.JPG

Personally i would never touch anything by a budget brand such as XFX. There is a reason we stopped stocking them... a 80% return rate! Any of the Corsair psu's, apart from the 430 are absolutely spot on. Remember though, corsair often under-rate their PSU, there is usually 20% more in them over what is advertised. So a 1Kw psu is actually a 1.2Kw psu.

deconduo

Komplett-Tech: Ryan wrote: »

Personally i would never touch anything by a budget brand such as XFX. There is a reason we stopped stocking them... a 80% return rate! Any of the Corsair psu's, apart from the 430 are absolutely spot on. Remember though, corsair often under-rate their PSU, there is usually 20% more in them over what is advertised. So a 1Kw psu is actually a 1.2Kw psu.

Their new Core Pro Series are actually quite good, though the 450W and 550W models do have a small problem with 12V regulation under heavy loads. Apart from that, they perform quite well.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=216
http://www.hardwaresecrets.com/article/XFX-PRO-750-W-Power-Supply-Review/1182

Monotype

What were returned by XFX? PSUs or GPUs/motherboards etc? I never returned my XFX 7900GT I bought from komplett!

Varik

Have a xfx 7800gtx that is over 6 years old and still works.

dwighet

Well lads while were on the subject of power supplies..
I will be changing my monitor to a 1200 res and adding another 6970(xfire) and a ssd to my kit soon and will be in need of a decent psu...Now my budget is around 150e for the psu give or take a score...

Im currently running 7 fans,i5 760 oced @ 4.2 ghz and a f3 hdd 1 gig..

What ye think I should get??

Serephucus

What's your current PSU?

deconduo

SuperFlower Amazon 800W would do you fine:

http://www1.hardwareversand.de/articledetail.jsp?aid=30071&agid=1630

Only problem is the €30 shipping from HWVS. However you can offset that by ordering the other parts from there as well.

darego

Komplett-Tech: Ryan wrote: »

Personally i would never touch anything by a budget brand such as XFX. There is a reason we stopped stocking them... a 80% return rate! Any of the Corsair psu's, apart from the 430 are absolutely spot on. Remember though, corsair often under-rate their PSU, there is usually 20% more in them over what is advertised. So a 1Kw psu is actually a 1.2Kw psu.

damn, too late order should be here on monday!

deconduo

darego wrote: »

damn, too late order should be here on monday!

Don't worry, as I said the Core Pro series are good quality. You should have no problems with them.

darego

good stuff!

dwighet

Serephucus wrote: »

What's your current PSU?

its a xilence 750.... I know its a piece of poo... dont be giving out now;)

dwighet

deconduo wrote: »

SuperFlower Amazon 800W would do you fine:

http://www1.hardwareversand.de/articledetail.jsp?aid=30071&agid=1630

Only problem is the €30 shipping from HWVS. However you can offset that by ordering the other parts from there as well.

Thats excacly what I was thinking of doing...;)
Is that a modular psu....Im a fussy fecker..

seyeM

Komplett-Tech: Ryan wrote: »

Personally i would never touch anything by a budget brand such as XFX. There is a reason we stopped stocking them... a 80% return rate! Any of the Corsair psu's, apart from the 430 are absolutely spot on. Remember though, corsair often under-rate their PSU, there is usually 20% more in them over what is advertised. So a 1Kw psu is actually a 1.2Kw psu.

The XFX PSUs are reported to be among the best value PSUs available today. They're rebranded Seasonic units, just like the Corsairs.

As a side note, it doesn't seem like Komplett stocks much of anything anymore :pac:

deconduo

dwighet wrote: »

Thats excacly what I was thinking of doing...;)
Is that a modular psu....Im a fussy fecker..

Nah its not unfortunately. You pay a premium for modular these days

http://www1.hardwareversand.de/articledetail.jsp?aid=33065&agid=1630
http://www1.hardwareversand.de/articledetail.jsp?aid=28060&agid=1630

The Golden Green is a better PSU, but the Corsair has a longer warranty.

Tea_Bag

Lads quick question, Will an 850W 80+ eff PSU cope with a rig running an OC'd i5-2500k (~4.5ghz) and 2x OC'd GTX 580's in SLI?

more specifically, a Cooler Master Silent Pro M850?

im looking at this PSU cause i currently have the Cooler Master Silent Pro M600w and its completely silent and so far has proven to be quite reliable. also, the modular aspect is a big plus.

EDIT: This theoretical system will be put under high stress because it'll be used with 3x 120hz 1080p monitors in 3D vision surround.

deconduo

You'd be cutting it pretty close. You're looking at 50A from the 580s and maybe ~12A from the rest of the system so a total of 62A on the +12V rail. While the PSU is rated for 66A its still a bit too close to comfort for me. I'd be looking for one with 72-75A.

Serephucus

Antec HCP-850 perhaps?

From what I've heard, the HCPs are very quiet units.

I myself am looking at the Revolution85+ from Enermax. They're supposed to be the quietest going.

http://www.watercoolinguk.co.uk/p/Enermax-Revolution85--ERV950EWT-950w-PSU_1412.html

79A total 12V.

Komplett-Tech: Ryan

Monotype wrote: »

What were returned by XFX? PSUs or GPUs/motherboards etc? I never returned my XFX 7900GT I bought from komplett!

Pretty much everything.

Tea_Bag

deconduo wrote: »

You'd be cutting it pretty close. You're looking at 50A from the 580s and maybe ~12A from the rest of the system so a total of 62A on the +12V rail. While the PSU is rated for 66A its still a bit too close to comfort for me. I'd be looking for one with 72-75A.

Thanks for the advice.
Looks like im going to either be needing a high end 850W PSU or a midrange 1KW.
with a budget limit of €150 im giving myself, and ordering from HWVS, the obvious choice of the Corsair HX1000W is out because of the €190 price tag,

ive narrowed it down to the CoolerMaster Silent Pro M1000 (brand loyalty i guess?) @ +12V - 80 A rail or the slightly more expensive Super Flower Golden Green SF-1000P14XE (80+ GOLD as upposed to CM silents 80+ bronze) @ +12V - 83 A according to HWVS.

anyone got any other suggestions for a PSU in the €150 or under bracket, or a PSU thats worth spending a tiny bit extra on?
Ideally, id like Modular and long cables, because cable management is hard enough already in my CM Storm Scout.

Any preference on the 2 i picked? i realise running SLI 580's on air isnt going to be quiet, but i want to add as little other noise as possible really. if i wanted to sit next to a jet engine while gaming, id keep playing on my xbox.

deconduo

The Golden Green is a better PSU but the CoolerMaster has a longer warranty. I'd take the Golden Green but its whatever you prefer. I would guess that the Golden Green would be quieter as well, SuperFlower have the quietest PSUs I've used

Tea_Bag

deconduo wrote: »

The Golden Green is a better PSU but the CoolerMaster has a longer warranty. I'd take the Golden Green but its whatever you prefer. I would guess that the Golden Green would be quieter as well, SuperFlower have the quietest PSUs I've used

Thanks Deconduo.

ill quote a PM i sent to a friend of mine rather than retype it:

i threw up an offer on an advert for a Corsair HX1000W PSU (new from HWVS is €190) and he accepted at €150 delivered. but its 10months old (not a problem as it has a 5 year warranty) but im wondering if its going to be worth the hassle to save €40?) Its pretty much the best 1kW PSU money can buy, but im not going to need it for at least 3 months really. my current PSU can suppost 1 GTX 580 and that was my part 1 upgrade: 1 GTX 580 and 1 3D screen. the second GTX 580 and 2 more screens at a later date.

for a saving of €38 i didnt really think it was worth going second hand and the risks associated with it, especially as the 2 i listed would do me fine, and that i might wait 3 months before i build this and see what Nvidia Keppler is like?

when do you think the 580 beating 600 series will hit the market? i dont want to have to wait till 2012. i figure the lower end 600 series is out this summer, with the big bad ugly out in early 2012?

Elisabeth Blanctorche

Hi guys just looking for some advice

Would this PSU:

http://www.scan.co.uk/products/500w-corsair-cmpsu-500cxuk-builder-series-80-eff-120mm-fan-single-rail-atx



Handle this graphis card http://www.scan.co.uk/products/1gb-msi-gtx-560-ti-twin-frozr-ii-oc-40nm-4200mhz-gddr5-gpu-880mhz-shader-1760mhz-384-cores

which pulls around 200w I believe at max load, and a 95w core i3, + standard sata3 hd.

Also is it any good? Are there newer or better corsair psu models available?

Thank you!

Elisabeth Blanctorche

Sorry I meant 65w cpu!

Solitaire

Possibly, although I don't trust the CX units; from what I've seen there's a new CX500 V2 doing the rounds with bad specs (<28A 12V rail instead of ~36A) and no reviews. Even the nice things some site said about the V1 have vanished into the ether, suggesting shillage. Corsair have shilled those units quite a bit while in reality there's a lot of "this PSU exploded!" comments mounting up on the bigger e-tailers' websites...

deconduo

Get this instead:
http://www.scan.co.uk/products/500w-silverstone-sst-st50f-es-strider-80-plus-80-eff-sli-crossfire-34db-eps-12v-120mm-fan

Only 2 pounds more and a much more solid unit. 34A instead of 28A on the +12V rail, 80+ and quieter.

Elisabeth Blanctorche

Thanks for the suggestion, I have never heard of that manufacturer though. Can you recommend a similarly priced Antec or Superflower?

Monotype

Silverstone are quite reliable, I bought one of these a while back for a cheap build. Looking at the OEM list now, I can see that it originates from Sirtec, which are mixed, but defintely better than shoddy PSUs and probably better than the CX.
IMO, this silverstone is good for the price (being modular). It's FSP, so I'm guessing it could be something similar to the StealthXStream II PSUs from OCZ. http://www.scan.co.uk/products/500w-silverstone-st50f-p-strider-silent-100-modular-80-plus-bronze-psu

I haven't seen superflowers stocked at all with UK and Irish sellers. One of the best budget antecs is he 650W earthwatts. A good PSU, but a bit more than what you're aming for.
http://www.scan.co.uk/products/650w-antec-ea-650-gb-earthwatts-80-plus-120mm-low-noise-fan

Take a look at seasonic's and enermax's offerings at that price.
http://www.scan.co.uk/products/520w-seasonic-s12ii-520-bronze-80-plus-bronze-85-eff-eps-12v-120mm-silent-s2fc-fan-atx-v23


Scan usually have PSU deals at the weekend, so you might find something of interest.

Elisabeth Blanctorche

Monotype wrote: »

Silverstone are quite reliable, I bought one of these a while back for a cheap build. Looking at the OEM list now, I can see that it originates from Sirtec, which are mixed, but defintely better than shoddy PSUs and probably better than the CX.
IMO, this silverstone is good for the price (being modular). It's FSP, so I'm guessing it could be something similar to the StealthXStream II PSUs from OCZ. http://www.scan.co.uk/products/500w-silverstone-st50f-p-strider-silent-100-modular-80-plus-bronze-psu

I haven't seen superflowers stocked at all with UK and Irish sellers. One of the best budget antecs is he 650W earthwatts. A good PSU, but a bit more than what you're aming for.
http://www.scan.co.uk/products/650w-antec-ea-650-gb-earthwatts-80-plus-120mm-low-noise-fan

Take a look at seasonic's and enermax's offerings at that price.
http://www.scan.co.uk/products/520w-seasonic-s12ii-520-bronze-80-plus-bronze-85-eff-eps-12v-120mm-silent-s2fc-fan-atx-v23


Scan usually have PSU deals at the weekend, so you might find something of interest.

Thanks for the recommendations!

Would you say this 430w seasonic
http://www.scan.co.uk/products/430w-seasonic-s12ii-430-bronze-80-plus-bronze-82-eff-eps-12v-120mm-fan


would handle my setup? (Geforce gtx 560 ti 1gb) which draws around 200w under max load + an intel i3 around 65w, and a seagate 7200rpm 1tb drive?

Jack Smith

I have a super flower amazon 550w that I bought from hardwareversand.de for a home build PC but it seems there is no power coming from it. I'm using a standard continental adaptor to plug it in but I was wondering was there a special one I need to buy or any other ideas to why it isn't working?

Monotype

If you have an electric kettle, you could probably use that if you think that it's the plug. It could be PSU though. They just die sometimes.

Check all of your connectors. Then check them again. Check that wall socket it working. If everything seems OK, you're going to have to find another PSU to try with the system or try that PSU with another system to find out where the problem is.

Jack Smith

It's a brand new PSU so I doubt that it's dead. On the plug on the PSU it says 16 amp but I can't find an adaptor (or a plug even) that is 16amps. They all seem to be 13amps?

poggy

Jack Smith wrote: »

It's a brand new PSU so I doubt that it's dead. On the plug on the PSU it says 16 amp but I can't find an adaptor (or a plug even) that is 16amps. They all seem to be 13amps?

16 amps seams very high that would be a power draw of over 3kW i would say any 13 amp fuse should be ok

deconduo

Jack Smith wrote: »

It's a brand new PSU so I doubt that it's dead. On the plug on the PSU it says 16 amp but I can't find an adaptor (or a plug even) that is 16amps. They all seem to be 13amps?

A 13A fuse is fine. I'd be very surprised if its the PSU thats the problem. Make sure the switch at the back of the PSU is on first. Also try manually starting the computer using a screwdriver on the start switch pins on your motherboard.

You should post the specs of your build, might make it easier to diagnose the problem.

Jack Smith

I have a core i5-2500k with an msi p67a-g45 motherboard. MY PSU is an Amazon super flower 80plus 550w. I have a 13a adaptor but I do think I need a 16amp one because it says 16amp on the plug of the PSU

poggy

Jack Smith wrote: »

I have a core i5-2500k with an msi p67a-g45 motherboard. MY PSU is an Amazon super flower 80plus 550w. I have a 13a adaptor but I do think I need a 16amp one because it says 16amp on the plug of the PSU

The most that PSU can draw before it will fail is a little over 3 amps with a 80% efficiency and 550w draw. so a 13 amp fuse will be grand, also in the impossible event you do draw more than 13 amps the fuse will just burn out.

Jack Smith

I managed to sort it out, thanks for your help

K.O.Kiki

Found this massive reviews database:

http://www.realhardtechx.com/index_archivos/PSUReviewDatabase.html

Monotype

A lot of the PSUs and systems discussed are obsolete. You'd probably be best off starting a new thread if you want to talk about modern PSUs.