How much power do I need?

[Pez D Spencer]

How much wattage do you think I can get by with? 550 or 600 enough?

Right now I have a CRAPPY 20 dollar Sparkle 400W in my current system which consists of a X1950 PRO 512MB, P4 530, SATA x 2, DVD RW, and Intel D915 board. I didn't have much faith in this PSU and figured it might last a week and then take the whole ship down with it but it's held up for over 6 months and still going strong.

I wanna get a good PSU for my new system but I don't wanna throw away money on wattage I'll never need or use.

Thanks for any advice.

 

[John]

There are many quality psu's available, but the Corsair 620W would do your rig some justice. It's only $116.90 AR @ ZZF

http://www.silentpcreview.com/article692-page1.html

 

[mpilchfamily]

As always John is right. But its important to note that you need to be more focused on the Amperage your system needs from the +12v rails more so then the total wattage of the PSU. Your system will need about 32A to 24A on the combined +12v rails for which the Corsair unit can easily supply. Even the 520W unit would offer plenty of power for your system and save you a few dollars.

 

[MarcVenice]

Dude, if you are going to spend 800-1000$ on 2 frigging videocards, then don't skimp on the PSU. I suggest the 620hx as well, with 50a combined on the 12v rails. The 520hx with 40a on the 12v rails might do the job as well, but what's 20$ more or less on a a 2-2.5k build? The power supply comes with 5 year warranty if im not mistaken, and will last long enough to power your next rig.

 

[BoomerD]

Originally posted by: MarcVenice
Dude, if you are going to spend 800-1000$ on 2 frigging videocards, then don't skimp on the PSU. I suggest the 620hx as well, with 50a combined on the 12v rails. The 520hx with 40a on the 12v rails might do the job as well, but what's 20$ more or less on a a 2-2.5k build? The power supply comes with 5 year warranty if im not mistaken, and will last long enough to power your next rig.

I agree. Too many people (me included) spend TONS of $$$ on their system, then try to scrimp on the PSU...the one component that can make or break a system...and take out lots of those expensive goodies when it fails...Do yourself and your system a favor...buy a QUALITY PSU.

 

[Heinrich]

I'm surprised that you folks are OKing a 620W or 520W for dual 8800GTX's. I have a Seasonic 600W and it is making a HORRIBLE SHRIEK at SLI with two 640MB GTS. SLIZone recommends a lot more for 2 8800GTXs. Do I have a defective seasonic?

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

 

[MarcVenice]

620w corsair should do the job just fine, with 50a it should be no problem. I said the 520hx might be tricky, that's it ...

That SLI zone link is PURE garbage, in fact its utter AND pure garbage.

 

[JAG87]

PC P&C Silencer 750W for hardwire or Silverstone Decathlon 750W if you like modular.

 

[MrDudeMan]

:roll: @ 750W

 

[JAG87]

Originally posted by: MrDudeMan
:roll: @ 750W

:laugh: @ you

do you have any first hand experience with that hardware to be able to recommend anything? with 620W you are really pushing it, you are asking for trouble with that setup. and please don't link me to the inquirer article where they run everything with a 550w psu, I dont care. I like my system to be 100% reliable, and with 620W corsair or not you are PUSHING IT. its very easy to do the math.

95W Q6600 (if he over clocks to 3.2-3.6 ghz which most people do, that becomes 160W-200W)
185W 8800 GTX x 2
50W EVGA 680i

RAM + HD + OPTICAL DRIVE + SOUND CARD + FANS + ALL THE OTHER BS
account another 100W comprehensive

so lets see, without any over clocking
95+185+185+50+100W = 615W

over clock that machine a tiny bit and you can enjoy BSODs and restarts of all kinds under load. Of course I did account 100W for the rest of the parts which is probably excessive, a realistic value would be more like 70W. But still, you are on the EDGE. Do you really want to spend all that money on a setup like that and have fear of plugging anything else into your psu? 750W is the sweet spot for a setup like that. Remember, calculate your watts and add 20% if you want a stable and reliable system. 615W x 1.20 = 738W

So I ask you MrDudeMan, come again?





PS. I hope the OP has learned something from this post, otherwise I just wasted my time, because I don't really care about convincing you.

 

[PurdueRy]

Originally posted by: JAG87

Originally posted by: MrDudeMan
:roll: @ 750W

:laugh: @ you

do you have any first hand experience with that hardware to be able to recommend anything? with 620W you are really pushing it, you are asking for trouble with that setup. and please don't link me to the inquirer article where they run everything with a 550w psu, I dont care. I like my system to be 100% reliable, and with 620W corsair or not you are PUSHING IT. its very easy to do the math.

95W Q6600 (if he over clocks to 3.2-3.6 ghz which most people do, that becomes 160W-200W)
185W 8800 GTX x 2
50W EVGA 680i

RAM + HD + OPTICAL DRIVE + SOUND CARD + FANS + ALL THE OTHER BS
account another 100W comprehensive

so lets see, without any over clocking
95+185+185+50+100W = 615W

over clock that machine a tiny bit and you can enjoy BSODs and restarts of all kinds under load. Of course I did account 100W for the rest of the parts which is probably excessive, a realistic value would be more like 70W. But still, you are on the EDGE. Do you really want to spend all that money on a setup like that and have fear of plugging anything else into your psu? 750W is the sweet spot for a setup like that. Remember, calculate your watts and add 20% if you want a stable and reliable system. 615W x 1.20 = 738W

So I ask you MrDudeMan, come again?

http://www.xbitlabs.com/articl.../msi8800gts-640_6.html

Your a bit over on your 8800GTX power requirements. They are 130W peak.

130 x 2 = 260 + 50+95+100 = 505 Max

505 x 1.2 = 606W

I think the 620W is more than enough.

However, I do think your 100W for "everything else" is over estimating as you said. Also this would assume that all hard drives are seeking, Graphics are going like crazy, CPU pushed to the max. Hard to do in real life.

 

[JAG87]

I do trust xbit labs, but those measurements are wrong. The card would not need 2 pci-e connectors if it peaked at 131W. the pci-e slot supplies 75W and each connector supplies 75W, so one 6 pin would have been plenty (150W) but the card has 2.

And yes, 100W for everything is and over estimate, some people like to do water cooling, add lights, bling, 100 fans, fans that absorb 2 amps each, you never know. so I always add 100W for all the accessories. I still think 620W is just enough, and with power you never go "just" enough. 750W is a safe purchase and will be more future proof.

 

[PurdueRy]

Originally posted by: JAG87
I do trust xbit labs, but those measurements are wrong. The card would not need 2 pci-e connectors if it peaked at 131W. the pci-e slot supplies 75W and each connector supplies 75W, so one 6 pin would have been plenty (150W) but the card has 2.

And yes, 100W for everything is and over estimate, some people like to do water cooling, add lights, bling, 100 fans, fans that absorb 2 amps each, you never know. so I always add 100W for all the accessories. I still think 620W is just enough, and with power you never go "just" enough. 750W is a safe purchase and will be more future proof.

There are other design considerations to having 2 six pin connectors other than the amount of power they can supply.

Before the PCPnC power supply I would recommend the Enermax Infiniti actually.

 

[jonnyGURU]

Originally posted by: Heinrich
I'm surprised that you folks are OKing a 620W or 520W for dual 8800GTX's. I have a Seasonic 600W and it is making a HORRIBLE SHRIEK at SLI with two 640MB GTS. SLIZone recommends a lot more for 2 8800GTXs. Do I have a defective seasonic?

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

I think people missed the fact that he's talking about the rig being built in his sig and are thinking this PSU is to power the single X1950XTX.

Personally, I wouldn't recommend a Corsair HX620W for G80 SLI. It's pushing it too hard. Sure, Corsair can do it for a show, but I wouldn't do it for the long haul.

The OP should consider at least an 720W or 750W from Enermax (Infiniti) or Ultra (SevenTeam OEM) or PCP&C (the Silencer) or a Silverstone Zeus (or equivalent Etasis) or the Antec Quattro.

 

[JAG87]

Originally posted by: jonnyGURU

Personally, I wouldn't recommend a Corsair HX620W for G80 SLI. It's pushing it too hard. Sure, Corsair can do it for a show, but I wouldn't do it for the long haul.

The OP should consider at least an 720W or 750W from Enermax (Infiniti) or Ultra (SevenTeam OEM) or PCP&C (the Silencer) or a Silverstone Zeus (or equivalent Etasis) or the Antec Quattro.

Thank you jonny. Maybe they will believe it when it comes from you.

PurdueRy, I completely agree about the Infinity, and I apologize for leaving it out. As it stands my recommendations are PC P&C Silencer 750W, Enermax Infinity 720W, and Silverstone Decathlon 750W, in that order.

 

[John]

Originally posted by: jonnyGURU

Originally posted by: Heinrich
I'm surprised that you folks are OKing a 620W or 520W for dual 8800GTX's. I have a Seasonic 600W and it is making a HORRIBLE SHRIEK at SLI with two 640MB GTS. SLIZone recommends a lot more for 2 8800GTXs. Do I have a defective seasonic?

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

I think people missed the fact that he's talking about the rig being built in his sig and are thinking this PSU is to power the single X1950XTX.

Personally, I wouldn't recommend a Corsair HX620W for G80 SLI. It's pushing it too hard. Sure, Corsair can do it for a show, but I wouldn't do it for the long haul.

The OP should consider at least an 720W or 750W from Enermax (Infiniti) or Ultra (SevenTeam OEM) or PCP&C (the Silencer) or a Silverstone Zeus (or equivalent Etasis) or the Antec Quattro.

I based my recommendation on the specs in the topic summary. The absolute max he would probably pull is 425-450W (68-73% max load on the HX620) from the psu while running 2x Orthos + rthdribl + copying gigs of data from one hdd to the other + ripping a dvd. How often would you even be under that kind of load?

The Corsair Ram guy says the HX620 will easily power a 2900XT Crossfire setup.

Anyhow, extra headroom is always good to have, but the OP doesn't seem like he's interested in future proofing anything. Then again I could be wrong.....

 

[JAG87]

Originally posted by: John

Originally posted by: jonnyGURU

Originally posted by: Heinrich
I'm surprised that you folks are OKing a 620W or 520W for dual 8800GTX's. I have a Seasonic 600W and it is making a HORRIBLE SHRIEK at SLI with two 640MB GTS. SLIZone recommends a lot more for 2 8800GTXs. Do I have a defective seasonic?

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

I think people missed the fact that he's talking about the rig being built in his sig and are thinking this PSU is to power the single X1950XTX.

Personally, I wouldn't recommend a Corsair HX620W for G80 SLI. It's pushing it too hard. Sure, Corsair can do it for a show, but I wouldn't do it for the long haul.

The OP should consider at least an 720W or 750W from Enermax (Infiniti) or Ultra (SevenTeam OEM) or PCP&C (the Silencer) or a Silverstone Zeus (or equivalent Etasis) or the Antec Quattro.

I based my recommendation on the specs in the topic summary. The absolute max he would probably pull is 425-450W (68-73% max load on the HX620) from the psu while running 2x Orthos + rthdribl + copying gigs of data from one hdd to the other + ripping a dvd. How often would you even be under that kind of load?

The Corsair Ram guy says the HX620 will easily power a 2900XT Crossfire setup.

the Corsair Ram Guy also works for Corsair, don't forget.

and you wish it will pull 450W. I can show you that my Galaxy is pulling more than 500W from the wall while I am gaming. And that is with 25% cpu usage in a game like BF2 for example, and mild/high SLI usage. Take into account 85% efficiency, and you end up with roughly 450W of DC power. If one were to do what you suggested with 4 threads of prime95 + rthdribl and so on, I assure you it will pull almost 700W from the wall which after efficiency is almost 600W. That is the DANGER ZONE for a 620W power supply. Yes this is an unrealistic situation, but a 620W power supply falls short of the 20% over dimension rule. when you wire a house with 15A outlets, do you use 15A wire or 20A wire? ask an electrician and see what he says.

OP play it safe. you are spending lots of cash on your parts, DONT be cheap on the PSU. I know I wasn't with my Galaxy, and I don't regret spending the extra 50 or 100 bucks for one second.

 

[PurdueRy]

Originally posted by: JAG87

Originally posted by: John

Originally posted by: jonnyGURU

Originally posted by: Heinrich
I'm surprised that you folks are OKing a 620W or 520W for dual 8800GTX's. I have a Seasonic 600W and it is making a HORRIBLE SHRIEK at SLI with two 640MB GTS. SLIZone recommends a lot more for 2 8800GTXs. Do I have a defective seasonic?

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

I think people missed the fact that he's talking about the rig being built in his sig and are thinking this PSU is to power the single X1950XTX.

Personally, I wouldn't recommend a Corsair HX620W for G80 SLI. It's pushing it too hard. Sure, Corsair can do it for a show, but I wouldn't do it for the long haul.

The OP should consider at least an 720W or 750W from Enermax (Infiniti) or Ultra (SevenTeam OEM) or PCP&C (the Silencer) or a Silverstone Zeus (or equivalent Etasis) or the Antec Quattro.

I based my recommendation on the specs in the topic summary. The absolute max he would probably pull is 425-450W (68-73% max load on the HX620) from the psu while running 2x Orthos + rthdribl + copying gigs of data from one hdd to the other + ripping a dvd. How often would you even be under that kind of load?

The Corsair Ram guy says the HX620 will easily power a 2900XT Crossfire setup.

the Corsair Ram Guy also works for Corsair, don't forget.

and you wish it will pull 450W. I can show you that my Galaxy is pulling more than 500W from the wall while I am gaming. And that is with 25% cpu usage in a game like BF2 for example, and mild/high SLI usage. Take into account 85% efficiency, and you end up with roughly 450W of DC power. If one were to do what you suggested with 4 threads of prime95 + rthdribl and so on, I assure you it will pull almost 700W from the wall which after efficiency is almost 600W. That is the DANGER ZONE for a 620W power supply. Yes this is an unrealistic situation, but a 620W power supply falls short of the 20% over dimension rule. when you wire a house with 15A outlets, do you use 15A wire or 20A wire? ask an electrician and see what he says.

OP play it safe. you are spending lots of cash on your parts, DONT be cheap on the PSU. I know I wasn't with my Galaxy, and I don't regret spending the extra 50 or 100 bucks for one second.

Not that I FULLY disagree with you. But you did play with the numbers a bit there

The galaxy is at most 80% or so efficient. Even if it was 85% efficient you are using 425W not 450W that you said. However, since its 80% efficient you are using 400W from the PSU

So if you are pulling 700W from the wall you are actually using 560W I would like to see a picture of you pulling 700W from the wall however. I haven't seen that happen even on top end systems.

I stick with my recommendation of the Enermax Infiniti

 

[John]

Originally posted by: JAG87
the Corsair Ram Guy also works for Corsair, don't forget.

and you wish it will pull 450W. I can show you that my Galaxy is pulling more than 500W from the wall while I am gaming. And that is with 25% cpu usage in a game like BF2 for example, and mild/high SLI usage. Take into account 85% efficiency, and you end up with roughly 450W of DC power. If one were to do what you suggested with 4 threads of prime95 + rthdribl and so on, I assure you it will pull almost 700W from the wall which after efficiency is almost 600W. That is the DANGER ZONE for a 620W power supply. Yes this is an unrealistic situation, but a 620W power supply falls short of the 20% over dimension rule. when you wire a house with 15A outlets, do you use 15A wire or 20A wire? ask an electrician and see what he says.

OP play it safe. you are spending lots of cash on your parts, DONT be cheap on the PSU. I know I wasn't with my Galaxy, and I don't regret spending the extra 50 or 100 bucks for one second.

500W x 82% efficiency = 410W

Your CPU is o/c'ed and easily consuming an extra 50W over a stock Q6600. Are your GTX's o/c'ed? Since you appear to possess a kill-a-watt, and have a system similar to what the OP is going to assemble, how about stressing your rig with the apps that I mentioned and posting the power consumption result?

700W from the wall.....come on now.

 

[PurdueRy]

http://www.buy.com/prod/antec-...loc/101/204697807.html

 

[JAG87]

Originally posted by: PurdueRy

Originally posted by: JAG87

Originally posted by: John

Originally posted by: jonnyGURU

Originally posted by: Heinrich
I'm surprised that you folks are OKing a 620W or 520W for dual 8800GTX's. I have a Seasonic 600W and it is making a HORRIBLE SHRIEK at SLI with two 640MB GTS. SLIZone recommends a lot more for 2 8800GTXs. Do I have a defective seasonic?

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

I think people missed the fact that he's talking about the rig being built in his sig and are thinking this PSU is to power the single X1950XTX.

Personally, I wouldn't recommend a Corsair HX620W for G80 SLI. It's pushing it too hard. Sure, Corsair can do it for a show, but I wouldn't do it for the long haul.

The OP should consider at least an 720W or 750W from Enermax (Infiniti) or Ultra (SevenTeam OEM) or PCP&C (the Silencer) or a Silverstone Zeus (or equivalent Etasis) or the Antec Quattro.

I based my recommendation on the specs in the topic summary. The absolute max he would probably pull is 425-450W (68-73% max load on the HX620) from the psu while running 2x Orthos + rthdribl + copying gigs of data from one hdd to the other + ripping a dvd. How often would you even be under that kind of load?

The Corsair Ram guy says the HX620 will easily power a 2900XT Crossfire setup.

the Corsair Ram Guy also works for Corsair, don't forget.

and you wish it will pull 450W. I can show you that my Galaxy is pulling more than 500W from the wall while I am gaming. And that is with 25% cpu usage in a game like BF2 for example, and mild/high SLI usage. Take into account 85% efficiency, and you end up with roughly 450W of DC power. If one were to do what you suggested with 4 threads of prime95 + rthdribl and so on, I assure you it will pull almost 700W from the wall which after efficiency is almost 600W. That is the DANGER ZONE for a 620W power supply. Yes this is an unrealistic situation, but a 620W power supply falls short of the 20% over dimension rule. when you wire a house with 15A outlets, do you use 15A wire or 20A wire? ask an electrician and see what he says.

OP play it safe. you are spending lots of cash on your parts, DONT be cheap on the PSU. I know I wasn't with my Galaxy, and I don't regret spending the extra 50 or 100 bucks for one second.

Not that I FULLY disagree with you. But you did play with the numbers a bit there

The galaxy is at most 80% or so efficient. Even if it was 85% efficient you are using 425W not 450W that you said. However, since its 80% efficient you are using 400W from the wall actually

So if you are pulling 700W from the wall you are actually using 560W I would like to see a picture of you pulling 700W from the wall however. I haven't seen that happen even on top end systems.

I stick with my recommendation of the Enermax Infiniti

I never tried to do quad prime + rthdribl and read/write stress. Its kind of silly like you said. But I am guesstimating that it would probably absorb around 600W, and with 80-85% efficiency ( http://www.enermax.com/english...t_Display1.asp?PrID=75 ), thats pretty much 700W from the wall.

Any kind of game stress (BF2 for example) takes more than 500W from the wall, and thats using my cpu around 25%, and my videocards aren't even being fully used (the temps are clearly lower than when Im running rthdribl).

Point is, a 620W power supply is "just" enough. And when you are spending and splurging like that on a system, no component should be "just" enough. Are his GTXs in SLI "just" enough? Is his Q6600 "just" enough? No, so why should the power supply be.

I perfectly agree with the Infinity 720W.

 

[JAG87]

Originally posted by: PurdueRy

The galaxy is at most 80% or so efficient. Even if it was 85% efficient you are using 425W not 450W that you said. However, since its 80% efficient you are using 400W from the wall actually

and I think you got mixed up there. 400W from the wall is 320W at 80% dude.

 

[PurdueRy]

Originally posted by: JAG87

Originally posted by: PurdueRy

The galaxy is at most 80% or so efficient. Even if it was 85% efficient you are using 425W not 450W that you said. However, since its 80% efficient you are using 400W from the wall actually

and I think you got mixed up there. 400W from the wall is 320W at 80% dude.

I meant to say 400W of power from the PSU, sorry

 

[JAG87]

Originally posted by: PurdueRy

Originally posted by: JAG87

Originally posted by: PurdueRy

The galaxy is at most 80% or so efficient. Even if it was 85% efficient you are using 425W not 450W that you said. However, since its 80% efficient you are using 400W from the wall actually

and I think you got mixed up there. 400W from the wall is 320W at 80% dude.

I meant to say 400W of power from the PSU, sorry

yup i figured.

 

[John]

Originally posted by: JAG87
I never tried to do quad prime + rthdribl and read/write stress. Its kind of silly like you said. But I am guesstimating that it would probably absorb around 600W, and with 80-85% efficiency ( http://www.enermax.com/english...t_Display1.asp?PrID=75 ), thats pretty much 700W from the wall.

Any kind of game stress (BF2 for example) takes more than 500W from the wall, and thats using my cpu around 25%, and my videocards aren't even being fully used (the temps are clearly lower than when Im running rthdribl).

Why quesstimate when you can test it for yourself and show us the facts? You're clearly overestimating again. How do you know your cpu is only at a 25% load? As I stated before your cpu pulls at least 50W+ more than a stock Q6600. Take your cpu and video cards to stock speeds and perform a full load test for us.

Point is, a 620W power supply is "just" enough. And when you are spending and splurging like that on a system, no component should be "just" enough. Are his GTXs in SLI "just" enough? Is his Q6600 "just" enough? No, so why should the power supply be.

Just enough would be a Corsair HX520

I perfectly agree with the Infinity 720W.

That's a solid choice and I've recommended it on several occasions. If the OP wants to drop $180+ on a psu for substantial headroom then by all means do it.