PSUs single 12v Rail or more?

Joshatdot · 21 Oct 2010

I just calc'ed the wattage THG did on various OC'd GTS 450s, including the Asus I am getting. The Asus peaked at 226w, that's 18.833 amps (226w/12v=18.833). My Antec 430w has 17a & 16a rails .. looks like I'll be fine with normal desktop usage, but I think it might struggle in 3D gaming.

AFAIK, current ATX PSU rail specs is limited to 240 VA. So the limit on a +12v rail is maxed at 20a (12v x 20a=240w), 5v is 48a (5v x 48a=240w), and 3.3v is 72.72a!!

I know the 5v and 3.3v max is unthinkable to reach .. but the 12v max is very close to the 226w of the Asus GTS 450. I am thinking of the Corsair 550w single +12v rail PSU.

sygnus21 · 21 Oct 2010

A 550 would work with your system, if you look at my system specs, I originally had an Antec Neo HE 550 power supply which worked like a charm.

However, you might consider getting something in the range of 650-700/750 for future upgrades, especially for your video cards.

For me, I went with this for my system - Antec Signature 850W. Now, I didn’t necessarily need an 850, but I did want something larger than a 650 (plus I really like the Antec signature 850) for future upgrades.

Bottom line…. A 550 would work for you, but to be safe and have breathing room for upgrades, think 650ish.

And if you do decide to get a 550, make sure it's a quality 550 from an reputable company. Antec for example has different lines of power supplies, and though i'd buy a 550 from them, I wouldn't get one of their lower line models. That's what I mean when I say quality. Same with Corsair.

Never skimp (go cheap) on a power supply!!!

My two cents

ken9122 · 21 Oct 2010

"Never skimp (go cheap) on a power supply!!!"

+1

LiquidSnak · 21 Oct 2010

If you want another HD, I would recommend minimum for your system 600W. 650 to be sure.

smarteyeball · 21 Oct 2010

sygnus21 said:

And if you do decide to get a 550, make sure it's a quality 550 from an reputable company.

Never skimp (go cheap) on a power supply!!!

Quality over (wattage) quantity. Depending on the model, some lower rated wattage PSU's can delivery more than their rating if they have the amps and build quality to back it up.

sygnus21 · 21 Oct 2010

smarteyeball said:

Quality over (wattage) quantity. Depending on the model, some lower rated wattage PSU's can delivery more than their rating if they have the amps and build quality to back it up.

Exactly. A good example of the above statement is this.... Antec NeoPower 550 Power Supply Review | Hardware Secrets. Unfortunately this PS is no longer available.

Fortunately I still have mine though :)

LiquidSnak · 21 Oct 2010

The Basiq 550 is a really nice PSU, very similar to the NeoPower.

sygnus21 · 21 Oct 2010

LiquidSnak said:

The Basiq 550 is a really nice PSU, very similar to the NeoPower.

Any reviews on it? That's what I look for when purchasing a power supply.

The reviews on my Antec Signature 850W is one of the main reasons I got it.

LiquidSnak · 21 Oct 2010

If I was a review writer, I'd write a review for it. It's a great power supply, very stable, runs cool.

linnemeyerhere · 23 Oct 2010

I've learned a valuable lesson with my first build yes 600w is a good starting point but as I became more knowledgeable and expanded the performance of my system now I hind sight two important points I will alway start first.
1) Quality case larger the better as air flow is key, classic styling will alway outlast the fads
2) Over purchase the PSU, my mind set is now 800w as a minimum and 1000+ even better.
The extra you spend now will pay off down the road as mobo's, cpu's and gpu's change the under pinnings are the rock solid base that never has to change again !