Power supply makers big SLI scam

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Algere

Platinum Member
Feb 29, 2004
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Originally posted by: F4810
If you look in your manual the 4 pin aux connector that goes into the mobo near the CPU is on one rail rated as 12v x 15amps. Everything else runs off the 12v x 18amp rail which includes the ATX connector and all the molexs etc.
Is that what it really says? :roll: I highly doubt one of the two +12V rails powers only the CPU & nothing else.


Originally posted by: F4810
What people are saying is that the 18amp rail is not enough for 2 video cards, hard drives, part power of the motherboard etc.
The 600W Noisetaker which has 18A on each rail (35A shared between both +12V rails) is VoodooPC's preferred PSU for their SLI rigs & according to said manual (mentioned above & if applicable to other PSUs), one rail powers the CPU, MB, & SATA connectors while rail #2 powers everything else FWIW.

P.S. Meant 18A max. allowed, meaning if 18A were utilized on 1 rail, 17A would be left on the other & vice versa but nevertheless, my original response still stands.


Originally posted by: F4810
What I am trying to find out is what exactly the 4 pin aux connector powers on the mobo
CPU
 

Algere

Platinum Member
Feb 29, 2004
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Originally posted by: F4810
Originally posted by: Algere
Originally posted by: cleanerPA
I have an Antec Neopower 480, which is a dual rail PS- is the ATX connector using one rail and the peripherals connected via
4-pin Molex connectors going to the other rail? What about the 4-pin aux. connector?
According to the Noisetaker 2.0 manual which may or may not be related to the Neopower, The 20/24 pin & the 4-pin aux. connectors (assuming it's the plug w/ the 2x2 pin config.) share the same +12V rail & the peripherals utilize the other +12V rail.

The neopower is different then. Can we attach photos as I can show you a picture of the relevant page in the manual.
I wish we could as I could attach a pic from the Noisetaker manual.

Update: Pic added
 

F4810

Member
Jan 4, 2005
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Originally posted by: Algere
Originally posted by: F4810
If you look in your manual the 4 pin aux connector that goes into the mobo near the CPU is on one rail rated as 12v x 15amps. Everything else runs off the 12v x 18amp rail which includes the ATX connector and all the molexs etc.
Is that what it really says? :roll: I highly doubt one of the two +12V rails powers only the CPU & nothing else.


Originally posted by: F4810
What people are saying is that the 18amp rail is not enough for 2 video cards, hard drives, part power of the motherboard etc.
The 600W Noisetaker which has 18A on each rail (35A shared between both +12V rails) is VoodooPC's preferred PSU for their SLI rigs & according to said manual (mentioned above & if applicable to other PSUs), one rail powers the CPU, MB, & SATA connectors while rail #2 powers everything else FWIW.

P.S. Meant 18A max. allowed, meaning if 18A were utilized on 1 rail, 17A would be left on the other & vice versa but nevertheless, my original response still stands.


Originally posted by: F4810
What I am trying to find out is what exactly the 4 pin aux connector powers on the mobo
CPU

How can it only power the CPU? Does that mean a seperate circuit just for the CPU power. If so then why would you need 15amps for the CPU only???

How do you attach a pic???
 

Algere

Platinum Member
Feb 29, 2004
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It doesn't, see Pic e.g. & AFAIK ithe aux. 4 pin is to the CPU what PCIe power plugs are to PCIe gfx cards.

EDIT: Doh!@ I meant it does. Not thinking too straight right now ergo the multitude of edits in my posts.
 

Algere

Platinum Member
Feb 29, 2004
2,157
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Same way you attach links. Reply > click http > enter relevant info away.

P.S. FWIW, the pic is image hosted by another party.
 

Algere

Platinum Member
Feb 29, 2004
2,157
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Wow that does look messed up (for Neopower owners), if that's the configuration current shipping Neopowers have.

The Noisetaker model that I have came out less than 3 months ago AFAIK. The way the Noisetaker's dual +12V rails are configured, it looks more "tuned" for PCIe & possibly SLI (never personally tested) than the Neopower which came out around mid 04' (pre-SLI) AFAIK.
 

cleanerPA

Member
Nov 27, 2001
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Okay, so it looks like I messed up when I selected the Neopower 480. Enermax Noisetaker 2.0 EG701AX-VE SFMA 2.0 SLI is the way to go?!? 18A on each rail, they claim that they separate the video card power feed from the CPU. After looking at the Antec manual, it looks like the Neopower is kind of messed up- everything but the peripherals feed off of 12V1. Would it make a difference that I have the 4-pin molex connector on my MB connected- it feeds off of 12V2 on my PS? I don't have a wiring schematic for my motherboard, I wonder if that helps at all. I'm only running a single 6600GT, so maybe it's moot for now.

I will probably upgrade to a better PS, but which is preferred- getting dual rail with 18A on each and divorced power feeds for the CPU and the video cards (ala Enermax referenced above) or getting one single honking rail, 36A or up?

Thanks for the knowledge.
 

Algere

Platinum Member
Feb 29, 2004
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Okay, so it looks like I messed up when I selected the Neopower 480.
Depends on your POV of the situation - unless you bought it recently :(

Enermax Noisetaker 2.0 EG701AX-VE SFMA 2.0 SLI is the way to go?!?
Looks like it, if VoodooPC is utilizing 'em in their SLI rigs. You would assume they test it out before offering it as an option - only option in fact.

they claim that they separate the video card power feed from the CPU
That's what the pic/my manual says.

After looking at the Antec manual, it looks like the Neopower is kind of messed up- everything but the peripherals feed off of 12V1
Actually it's vice versa, CPU is powered by rail 2 and everything else is powered by rail 1 & that's what I got too, unless we 3 interpreted it wrong.

Would it make a difference that I have the 4-pin molex connector on my MB connected- it feeds off of 12V2 on my PS?
I'd say so (never tried), it's there for a reason.

I will probably upgrade to a better PS, but which is preferred- getting dual rail with 18A on each and divorced power feeds for the CPU and the video cards (ala Enermax referenced above) or getting one single honking rail, 36A or up?
As mentioned, dual rails increase stability but with single rails you might get a bit more ampage (is that even a word?) over dual rails since it's not split but then again it depends on what components are attached to what rail which determines how well the amps are utilized. So figure stability against a bit more ampage. IDK if this is fact or not so take it as speculation but "maybe" PSU's that utilize a single rail configuration suffer stability problems when their max amp output is utilized, unlike dual rail when theirs are utilized.
 

cleanerPA

Member
Nov 27, 2001
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Yes, I got the Neopower very recently- last week. Looked like the best power supply that I could get locally. There's a computer show this weekend- I might go and see if I can get the Enermax- or not.

Is it safe to assume that if the system is running fine as-is with the Neopower (remember, I'm not doing SLI right now, probably not ever) that I can just stay happy with it until I do a major configuration change? If the Neopower is powering the CPU on one rail and everything else on the other rail, I'm not presenting it with a really lopsided power demand so long as I remain with a single video card, esp. one like the 6600GT, which is much lower power consumption than a 6800GT.

I'm going to be building a HTPC in the near future anyway- I can use the Neopower in that system (it's fairly quiet) and then get either the Enermax that I mentioned above or something else? I don't see any dual-rail PSUs with over 18A on each rail. I guess I should also look at the single-rail PSUs- Antec EPS 550 or Enermax equivalent?

Thanks again for the info.
 

Algere

Platinum Member
Feb 29, 2004
2,157
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If you're not doing SLI you'll be fine. The predicament with the Neopower arises when 2 power hungry gfx cards attempt to suck juice from the rail that isn't related to the CPU since it's being taxed by everything else as you obviously know already. You might be able to do SLI with the Neopower but if you should do so remember that the lesser amount of devices (i.e. hard drives) connected to the same rail as the gfx cards, the more amps available for the gfx cards to use.

Here's a link to another thread I've responded to (won't burden this thread with a long requote ;)) with a bit more of personal insight about the Neopower. Lastly, by the time you look for a PSU replacement. I'm willing to bet there will be +18A dual rail PSUs out by then.

 

shira

Diamond Member
Jan 12, 2005
9,500
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Originally posted by: GuitarDaddy
Don't buy a multiple rail power supply for your SLI rig! And if you have one RMA it while you still can!

A corollary:

If you plan on NOT using dual video cards with the PS you're about to purchase, getting a high-quality dual-rail PS would probably be a good idea, since the power fluctuations caused by the video card will be isolated from the rest of the PC.

 

cleanerPA

Member
Nov 27, 2001
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Algere- Thanks for the info- it looks like I'll be getting an Enermax (the one Voodoo PC uses) in order to keep myself open to the option of SLI in the future. I'm not one to continually upgrade my system, so I'd like to get a few years out of the system just by doing an upgrade here or there.

I'm learning that not keeping up with the latest can definitely cost you- that was a $120 mistake, considering the Enermax isn't much more.
 

cleanerPA

Member
Nov 27, 2001
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Niceguy- thanks for the pointer- I didn't fully understand the concept of a dual rail PSU when I read the thread you reference. Now that I have a little bit of a clue, I can at least say that I didn't screw up the rest of my purchase decisions.
:)
 

michaeldorian

Member
Dec 10, 2004
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Originally posted by: dgevert
Single, 34-38A on 12V rail

Originally posted by: Insomniak
Dual 12v rails is a minus. Avoid if possible...you want one strong 12v rail.

Hi,

I was wondering though as Alienware list there Turbo Cool 510 as a dual rail PSU. Do you know if it is a single or dual rail PSU? IS alienware running there own custom designed 510 on there 7500 SLI? Cuas ethe specs on alienware list the PSU as a dual rail? ANy ideas?

http://www.alienware.com/Confi...emId=12604&ItemIdList=

From there website for there 7500 SLI system

PCI-Express Ready
Alienware high-performance systems designed with PCI Express, the next-generation standard in graphics and system bus performance, make full use of Turbo-Cool 510 Deluxe PCI Express-ready power supplies. Specifically designed to support PCI Express power requirements, these power supply units feature robust 24-pin ATX power mains and dual 12 volt lines. This provides dedicated 12 volt power to critical system components - such as the system processor, graphics processor, and hard drives - to ensure maximum reliability and unshakeable stability.

Peak Power 650W

Continuous Power 510W

DC Output +5V @ 40A
+12V1 @ 18A
+12V2 @ 16A
-5V @ 0.3A
-12V @ 2.0A
+3.3V @ 30A
+5VSB @ 3.0A

Fan Type 30 - 44 CFM ball bearing

Noise 34 - 44 dB

Mean Time Before Failure 100,000 hours

Looks like there is a 12V1 and a 12V2 rail.


Any clarification is greatly appreciated. I really wait to buy this PSU but want to make sure.



 

Algere

Platinum Member
Feb 29, 2004
2,157
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Finally, it comes out - nice price :thumbsup:. I too will add fuel to the fire by saying it'll work with SLI. :p
 

danyblasco

Junior Member
Jan 31, 2005
5
0
0
HI, after reading you article I wonder if i purchased the right power supplay, I am planning in building an sli system and i got the power supplay by enermax,sli ready, model#EG565P-VE, is 24 pin dc output total power 535 W, would you please let me know. Thank you .Daniel
 
Jan 27, 2005
27
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Originally posted by: michaeldorian
Can anyone confirm if the PC Power and Cooling 510 SLI is a dual or single rail PS?


I believe it has a single 12V rail. The label on my 510-SLI gives it's 12V max current as a single number, not 12V1 and 12V2.

http://www.pcpowercooling.com/pdf/510-SLI.pdf

It's interesting that this supply is advertised to give 510W @ 50 Deg-C and PC P&C is guarenteeing it to operate any SLI system.

Given the advertised numbers for this power supply, I think it'll be just fine without a second 12V rail.

- Marcos
 

VirtualLarry

No Lifer
Aug 25, 2001
56,574
10,211
126
Originally posted by: bluslice
i don't know very much about japanese PSU's but you can't base your use of that POS and say that all dual 12v rail PSU's are crap. If you buy from OCZ, Enermax, Antec...etc., then you'll be getting quality and stable power. By an american PSU. USA!!
That was made by a major far-east OEM in a Chinese factor? Hmm? I think that you need to understand who actually makes those "big name US brands". They made be designed/engineered by Americans, but I don't know of any that are actually made here. At least not in mass qtys.