psu rquired for wc

opstrat · 20 Mar 2012 at 17:13

iv opend a can or worms here.

as in the origional post i have a 2500k at 4ghz and one 6850 i want to wc the the proccessor then later add 1 EVGA 3gig 580 and watercool that.

iv went down the road of xfire when i played with eyefinity and didnt like the hassle it created. hence the large vram card.

opinions are split here which make it harder to decide.

rjk · 20 Mar 2012 at 17:17

watercooling will add about the same power draw as a few fans at the very most.

a single graphics card of any power requirement and a single cpu

will draw less than 650w. this is a fact.

I work for OcUK, if anything, I should be the one trying to sell you a PSU you don't need.

the fact is, that I am not

opstrat · 20 Mar 2012 at 17:32

lol fair point.

also from ur build logs u used a 750 and 850 on them.

advice taken

problem is the likes of
http://www.overclockers.co.uk/showproduct.php?prodid=CA-027-CS&groupid=701&catid=123&subcat=1084

is £130 for that i can get a silverstone fully modular 1000w for the same price. (this isnt a dig at ocuk prices i know corsair is expensive no matter whare u go).

all the others are only semi modular

ovia · 20 Mar 2012 at 18:58

850 is suffucuent.

I run on a OCZ 850W PSU the following:

E6600 @ 3.2
2 x 8800GTX overclocked (forget what to now

)
Water Pump
6 x 120mm fans
3 Hard Drives

And i have had more on it, you dont need to go silly. Im about to upgrade with water cooling and the new Nvidia card and a i5 and still sticking with a 850W PSU.

Cleeecooo · 20 Mar 2012 at 20:44

rjkoneill said:
and it will be operating outside of its efficiency.

a 990X at 5GHz and a PAIR of overclocked GTX590s at max load draw less than 600W from the wall.

remember this when you are instructing people to go and buy expensive 1Kw units that they don't really need.

But why get an 850w when you can get 1kw for £20 more?

ST1000P £130 (£0.13/W)
ST850P £110 (£0.13/W)

It's basic human psychology to simply say "it's only £20 more for 150w"

I'm by no means saying buy an OEM 1kw over a Seasonic 850w, but when comparing two high quality PSU's there's not a huge difference in cost relative to the full price of each unit. In the example I gave above, they have the same price/watt.

The fact remains, there's so little difference in price that you're not exactly harming your computer by getting a more powerful PSU. Will that £20 going spare in your budget really help out elsewhere? I'm not saying that if you have an 850 you need a 1kw PSU, but it's like gfx cards vram. You can have a 1.5gb card that may be suitable for your needs by a huge margin, bu you'd rather have the 3gb version for £30 more, even if you don't need it. It's good for the e-peen.

Tefal · 20 Mar 2012 at 23:15

Cleeecooo said:
But why get an 850w when you can get 1kw for £20 more?

because adults have to pay the electricity bill, and running a 1kw psu well out of it's efficiency zone will cost more.

Krony · 20 Mar 2012 at 23:44

Still say 850w if u are planning sli in the future, my X58 system will use more than the OP's P67 system and with running fairly high overclocks of 950MHz i have peaked at around 900w(810w 90% efficiency) from the wall.

TwsT · 21 Mar 2012 at 07:15

just to clarify. I run a

Asus maximius Extreme Gene Z
16gb ram
2500k @ 4.5 GHz
2 X ssd in raid 0
a water cooling loop
a GTX 580
a blue ray drive
3 mechanical drives
an asus d2x sound card

on an XFX pro 650W it hasn't crashed out due to power once. I've had 2 460's in SLI on it too.

RJC · 21 Mar 2012 at 07:35

I can't remember the actual figure but my system pulled around 400w ~ (in sig) with Furmark and prime running together.

My old 920 system was around 530w~

rjk · 21 Mar 2012 at 11:25

Cleeecooo said:
But why get an 850w when you can get 1kw for £20 more?

read my reply that you quoted...

rjkoneill said:
and it will be operating outside of its efficiency.

my point is, why get a massive overpowered psu that you dont need, if you want to spend a lot of money, get a lower wattage psu which is suited to your system and spend the money on additional features. like full modularity, thermal control, silent fans, larger warranties etc etc.

The system I measured with the 5GHz 990X and 590SLI pulls over 400w LESS than the rated wattage of the supplies you are suggesting.
I would take a guess that the system mentioned in the OP could run on a 400W corsair.
add a 580 into the equation you would be looking at needing maybe a 500w

so us suggesting 750w> supplies is STILL overkill.

a psu outside its efficiency band is pointless, that £20+ could be spent on useful stuff

Tefal said:
because adults have to pay the electricity bill, and running a 1kw psu well out of it's efficiency zone will cost more.

rjk · 21 Mar 2012 at 11:38

opstrat said:
problem is the likes of
http://www.overclockers.co.uk/showproduct.php?prodid=CA-027-CS&groupid=701&catid=123&subcat=1084

is £130 for that i can get a silverstone fully modular 1000w for the same price. (this isnt a dig at ocuk prices i know corsair is expensive no matter whare u go).

all the others are only semi modular

and all supplies which are more expensive than that are not required unless you are running:

Triple GPU configurations
Multi CPU configurations
huge storage arrays

the fact is, that the op of this thread was a request for a mid range supply. nothing more, suggesting anything else is not answering the question properly.

Cleeecooo · 21 Mar 2012 at 18:12

Tefal said:
because adults have to pay the electricity bill

Grow up. EDF doesn't give me my energy for free.

Tefal said:
and running a 1kw psu well out of it's efficiency zone will cost more.

Is that really a factor worth considering when that price is so small?
What about when (if) you get a more powerful system which will make the lower wattage PSU run at a lesser efficiency? Granted, we are talking about the current situation so that last point is somewhat invalid.

rjkoneill said:
read my reply that you quoted...

I read that bit, but what i'm arguing is that it's not worth taking that into account when it'll cost you <£5 per annum for efficiency loss, when/if you do later upgrade your system, you may need to spend more selling a PSU and buying a more powerful one.

my point is, why get a massive overpowered psu that you dont need, if you want to spend a lot of money, get a lower wattage psu which is suited to your system and spend the money on additional features. like full modularity, thermal control, silent fans, larger warranties etc etc.

I wasn't saying when you've got a 400w perfect for your system, go for a 1kw PSU, but if you've already decided on a PSU you want and the upper model is slightly more and you feel that in the future you may decide you will use the extra power, then it's a good decision to get the upper model.

The system I measured with the 5GHz 990X and 590SLI pulls over 400w LESS than the rated wattage of the supplies you are suggesting.
I would take a guess that the system mentioned in the OP could run on a 400W corsair.
add a 580 into the equation you would be looking at needing maybe a 500w

so us suggesting 750w> supplies is STILL overkill.

a psu outside its efficiency band is pointless, that £20+ could be spent on useful stuff

or; it could be spent preparing your computer for future upgrades (obviously, this doesn't apply if you plan to keep the system for years upon years)

Krony · 22 Mar 2012 at 01:40

Hey, i have an Antec HCP 1200w running only sli 580's

Why ? idk, possibly of tri sli ? hell could easily run quad with dual cpu's with what i have got but the fan never spins

and it's a quality psu and i should never need to buy a new psu for the next few years for a small premium now.

CaptainUnlikely · 22 Mar 2012 at 03:25

Krony said:
Hey, i have an Antec HCP 1200w running only sli 580's
Why ? idk, possibly of tri sli ? hell could easily run quad with dual cpu's with what i have got but the fan never spins and it's a quality psu and i should never need to buy a new psu for the next few years for a small premium now.

You win!
Oh wait, no you don't.
Your PSU is complete and utter monster overkill and over twice as much as you needed to spend for a good quality unit. Yes, it's excellent quality, but it's a completely wasted investment.
Plus the fan should be spinning all the time so I'd return that ASAP, even though you'll be pulling less than half of its rated wattage.

Krony · 22 Mar 2012 at 04:05

Actually i have pulled just over 2/3 of it's total rated output and yes the fan does spin but it spins at it's normal idle speed even at that wattage, as i said i was looking at maybe going tri sli and with some decent overclocking i think i could have pushed it way past the 1000w area, if u read earlyer posts in this thread u will notice i recomended a decent quality 850w psu for sli 580's and that recomendation still stands.

CaptainUnlikely · 22 Mar 2012 at 08:02

Just over 2/3 from the wall, or the PSU? How did you measure it?
I'd expect the fan to be spinning at idle speeds when you're nowhere near taxing the PSU, yes, you wrote that it wasn't spinning hence my concern.
A good 750 is enough for your system, with heavily overclocked and overvolted tried SLI 580s and a heavily overclocked and overvolted CPU then it's just about possible you'd break 1000W but you'd have to go really crazy.
In any case, the OP has a SB chip which will use nowhere near the wattage your 950 does, his system is much less power hungry hence the recommendation for a good 650 or 750.

Krony · 22 Mar 2012 at 12:44

900w from the wall which is around 810w, the SB will use less as i have already stated in previous posts in this thread, a lot depends on overclocking, if he is interested in benchmarking and pushing his system then a 650 or 750 will be pushing it a bit.

opstrat · 22 Mar 2012 at 15:14

Krony said:
900w from the wall which is around 810w, the SB will use less as i have already stated in previous posts in this thread, a lot depends on overclocking, if he is interested in benchmarking and pushing his system then a 650 or 750 will be pushing it a bit.

im running at 4ghz. mainly becasue the board is a msi z68g43 http://uk.msi.com/product/mb/Z68A-G43--G3-.html
which isnt the best for overclocking.

PhilthyPhil · 22 Mar 2012 at 21:39

Isn't a PSU typically most efficient at about 50% load? So using an overspeced PSU would actually be more efficient?

Krony · 23 Mar 2012 at 00:59

Not my words just something i copied.

The most basic and original certification - 80 PLUS - is awarded to any power supply capable of achieving at least 80 per cent efficiency at the three defined workloads. An 80 PLUS Gold certification, meanwhile, can only be awarded to power supplies capable of achieving 88 per cent efficiency at 20 per cent load, 92 per cent efficiency at 50 per cent load and 88 per cent efficiency at 100 per cent load

All five standards are defined as follows:

80 PLUS 80% 80% 80%
80 PLUS Bronze 81% 85% 81%
80 PLUS Silver 85% 89% 85%
80 PLUS Gold 88% 92% 88%
80 PLUS Platinum 90% 94% 91%

So basically as we have alreadty mentioned the quality of the PSU is the most important thing to look at when buying one, and going a bit bigger than u currently need is always gonna give u bit more future proofing which is not a saying i like to use frequently as so called future proofing might only mean a few months with certain areas of hardware, as for PSU's tho we are talking the heart of the PC and it's the component most ppl try and save money on, if u do buy a bigger PSU that is 80+ gold or even platinum then u are not going to be running it out of it's efficency unless it is extremely overkill for what u are looking at, i.e. running nit lower than 20% load most of the time.