12v rails

[cattb]

I have question on 12V rails on PSU.
I have 22A rails, also can be set up for SLI on my PSU. It is a 500 watt earthwatts Antec.
I was looking at a nvidia 260,36 amp on rail advised, (see below)

Minimum of a 500 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 36 Amp Amps.)
Two available 6-pin Molex hard drive power dongles

Does this mean I need 36Amp per rail? Or does this mean I need 36 Amp total between both rails?

If anyone knows a good article I could read on the net to explain these PSU's and rails please post, I would like to learn more about this.

I am going to upgrade 1 day but not very soon, I would just like to learn about it so when the day comes I can be prepared. 
Thanks Tim O/ cattb






I

[zmeg]

  The 260 is rated at 182 watts,that's just over 15 amps. 22 amps per rail is plenty.

[RipChord929]

Was just looking at the specs on Newegg for that unit...
It says 2 x 12V rails at 17amps each..
That means only 34amps total when wired in parallel...

I've read that those new 2 series cards are mighty power hungry..
Thats cuttin it a little close to the limit... More would be better!!!

I'd get a bigger PSU just to be sure... Besides a little overkill never
hurts in the PSU department... Then you'll have room to upgrade later
as well... Add fans etc etc... Just my 2c, for what its worth...

RC

[Ghastly]

This is why I dislike multi-rail power supplies.  I can't get the Antec site to come up at all, but from what I can tell from the NewEgg site, this P/S has 1 rail (at 17@) for "motherboard and peripherals" and the other (at 17 amps) for the processor.  

This means that both molex connectors are likely on the same rail at a max of 17 amps, so given that the GTX 260 pulls about 180 watts at peak, you're going to be pulling 15 amps or so at max just for the video card - in other words, way WAY under powered on that rail.

All supposition, because I don't know exactly how much amperage whatever card you want will draw, or how the P/S is wired - But my guess is that it won't run properly.

<S>

[RipChord929]

Good point, LOL!!!   If the 2 rails are both supplied by the same 17amp source within the power supply, then they will only have 17amps.. Whether wired in parallel to the load or not, LOL!!!  Must be one of those marketing gimmicks again... Hate when they do that!!! Wonder how many ppl are skrewed because of that?

750 and 800watt PSU's are becoming the single GPU, "gaming standard" aren't they?

One big fat rail w 70 or 80 amps is better, no doubt!

RC

[Masherbrum]

  The 260 is rated at 182 watts,that's just over 15 amps. 22 amps per rail is plenty.

What?!

The GTX 260 needs a minimum of 500 Watt PSU and a minimum of 36A combined on the +12V rail.   22 Amps will destroy the GTX 260 over time due to "under powering".

The GTS 250 needs a minimum of 450 Watt PSU and a minimum of 24A combined on the +12V rail.   22 Amps will destroy this card as well over time due to "under powering". 

I hope the OP uses Manufacturer Specifications as just a foundation and over compensates for other components of the PC and not just the GPU.    100% of the time with PC's, it is better to have more Watts, than too little.   You're screwed if it's the latter, because it is money wasted. 

[Masherbrum]

I have question on 12V rails on PSU.
I have 22A rails, also can be set up for SLI on my PSU. It is a 500 watt earthwatts Antec.
I was looking at a nvidia 260,36 amp on rail advised, (see below)

Minimum of a 500 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 36 Amp Amps.)
Two available 6-pin Molex hard drive power dongles

Does this mean I need 36Amp per rail? Or does this mean I need 36 Amp total between both rails?

If anyone knows a good article I could read on the net to explain these PSU's and rails please post, I would like to learn more about this.

I am going to upgrade 1 day but not very soon, I would just like to learn about it so when the day comes I can be prepared. 
Thanks Tim O/ cattb

If it's http://www.antec.com/Believe_it/product.php?id=NjU=, you are cutting it close.   You have 2 x 22 Amp +12V rails giving you 44 Amps total.   You're cutting it close for an entire system IMO.   Keep in mind, Antec PSU's are nothing like they used to be.  Being an Antec, I'd suspect you could knock several amps off of the "total".   

[cattb]

Thanks for the post and help
TimO/Cattb