Choosing PSU for Fermi. What do I need to look for?(beside wattage)

[lgmcben]

Hi.

Sorry for this newby question. Last time I build a system was 6-7 years ago. And it's still my current system: Pentium 4 3.0GHz, 6600GT AGP.

Long story short:
I'm choosing a PSU for i7930 + GTX 480. What do I need to know other than wattage? What is +12v rails, single rail, quad rails? ..... Do I need that stuff for Fermi?

My local store have these 2 models which probably will do the job
This one has four +12V rails
http://thermaltakeusa.com/Product.aspx?C=1264&ID=1502

This one says: "Single +12V rail for the most demanding SLI configurations"
http://www.coolermaster.com/product.php?product_id=6643

Thank you in advance!

 

[obsidian86]

perfect for a single gtx 480<===

just kidding

but thermaltake and cooler master a bit iffy

a good psu is a good psu irrespective of how many rails it has

the gtx could have a tdp of up to 290watts same as a gtx 295 so i'd say least a good 650 watts for a single card and round 850 for dual cards

 

[moody89]

From what I've heard the minimum power requirements for a GTX 480 is:

A minimum of 600W total system power.

A minimum of 42A on the +12V rails.

Obviously you need your PCI-E connector for your card too. Most high-quality PSUs that provide 600W will have more than 42A on the +12V rails. I would recommend Corsair primarily but others include Antec, Seasonic etc. Don't forget that the 42A is for the whole system not just your GPU so don't worry about that. It shouldn't matter whether your PSU has a single or multiple +12V rails as long as they provide the necessary amperage. If you're unsure of the amperage a PSU provides check the manufacturer's website or post back here if you're stuck. Any decent PSU manufacturer will have their ratings on their website.

 

[jsc]

A Corsair 550VX with its 41 amp 12 volt rail would work. But I would go one size larger to the 650TX -
Corsair 650TX (52 amp 12 volt rail)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005

I agree with obsidian86 on this: I would not use ThermalTake or CoolerMaster PSU's to power any system I had significant money in.

 

[JohnnyLucky]

I have a better recommendation. There has been too much speculation and a lot of unsubstantiated rumors. Let's just wait a couple of days for the official release. Most of the time a few technical reviews are published on the day of release. Wouldn't hurt to wait until we had solid information about system requirements and power consumption. This Friday is the big day. It is less than 48 hours away.

 

[mindless728]

perfect for a single gtx 480<===

just kidding

but thermaltake and cooler master a bit iffy

a good psu is a good psu irrespective of how many rails it has

the gtx could have a tdp of up to 290watts same as a gtx 295 so i'd say least a good 650 watts for a single card and round 850 for dual cards

dude, 40A from a 120 line is absurd, though i would imagine it would power it

though like JohnnyLucky said, wait for the cards to be released to see what you need

 

[darkguset]

What do you need to look for? An actual Fermi card first, then you can look for the rest...

 

[JohnnyLucky]

In the meantime.....

A +12 volt rail supplies power to the cpu, the video card, and some other components. The +12 volt rail delivers about about 75% of the power used by a system. There are other rails with other voltages that also deliver power to other components.

Here is a link to an excellent explanation about multiple +12 volt rails posted by Jonny Guru:

http://www.jonnyguru.com/forums/showthread.php?t=3990

 

[lgmcben]

Best answer selected by lgmcben.