Help choosing PSU

blade_146 · Post by **blade_146** » Sun Feb 22, 2009 1:30 pm

I got my income tax back and Im planning on building a new rig after 4 yrs!! I havent decided yet on I7 or the Phenom II but i need help on choosing the right PSU. What exactly is the difference in single rail and multi 12v rails?
Heres the 2 im looking at

http://www.newegg.com/Product/Product.a ... 6817371017

http://www.newegg.com/Product/Product.a ... 6817139005

Post by **FlyingPenguin** » Sun Feb 22, 2009 3:36 pm

Do NOT buy anything less than a dual rail 12 volt power supply.

The idea is that you do not want the video card and the rest of the computer on the same rail since the power draw of the vid card can jump up and down very dramatically. Having 2 or more rails isolates the rest of the system from voltage fluctuations on the vid card's 12 volt rail.

Most decent gamer grade PSUs are 3 rails and if you have a high end vid card like the NVidia GTX 260 that uses two 6 pin power plugs, then 3 rails is a minimum. 3 or 4 rails is required for SLI.

For modern gaming you don't want anything less than a total of 50 amps adding up all the +12 volt rails. More would be better.

I would also avoid Antec nowadays. They aren't the quality they used to be.

Also I wouldn't buy anything that isn't at least 80 plus certified. This rating means that the PSU is more than 80 percent efficient, and when the system is idling it uses a minimum of power.

I just bought one of these which has four 20 amp rails. Not a pretty looking PSU if that matters to you, but good specs for the money and good reviews. Also very quiet and runs cool which is important to me: http://www.newegg.com/Product/Product.a ... 6817182160

Rock solid for the past 2 months running a GTX 260.

Just skimming the sales page on Newegg I saw this one which is a nice deal after rebate and they give you a free DVD burner with it: http://www.newegg.com/Product/Product.a ... 6817341018

I've had good luck with Rosewill, OCZ, Coolermaster & Corsair.

Key Keeper · Post by **Key Keeper** » Sun Feb 22, 2009 4:16 pm

Silverstone....They are super quiet and rock solid. Ive had the same one for 4 years and its never gave me problems. 650w or bigger with a single 120mm fan or larger.

b-man1 · Post by **b-man1** » Sun Feb 22, 2009 6:27 pm

good deal posted a few days ago here too:

http://www.pcabusers.com/forums/showthread.php?t=47578

blade_146 · Post by **blade_146** » Wed Feb 25, 2009 4:08 pm

Well I wound up going with thishttp://www.newegg.com/Product/Product.aspx?Item=N82E16817153039

and this case http://www.newegg.com/Product/Product.a ... 6811129021

I hope those are good parts. I think they are anyway.
Now I have to decide on the rest of it.

Man those I7's and the mobo to run them are high as hell. Almost forgot about a new video card too. Jeesh this is adding up but its so much fun!!

Post by **FlyingPenguin** » Thu Feb 26, 2009 12:27 am

Well I didn't know you were trying to spend as much money as possible, or I would have made some different recommendations

Yeah that's a nice quality PSU, but you could have saved a bit of money. Heck that Rosewill PSU I linked to actually has 8 more amps on the 12 volt rail despite the fact that it's rated for 530 watts.

As I've said many times before, wattage ratings are totally bogus. Rosewill is honest and doesn't use the MAX wattage as the wattage rating for the unit (if it did then it would be a 630 watt PSU). Meanwhile Thermaltake, like most manufacturers, uses the inflated MAX rating because it looks more impressive.

The Thermaltake has a heavier 3.3 volt rail which is nice if you plan on overclocking, but on most PSUs the 5 volt and 3.3 volt rails are really meaningless. It's the 12 volt rail that matters. I agree the Thermaltake is probably a better quality unit but is that quality worth more than twice the price?

blade_146 · Post by **blade_146** » Thu Feb 26, 2009 8:47 am

I wanted the modular cabling first and foremost. Im sick of a crap ton of cables that I dont use. Im anal like that I guess

But to answer your question..no it probably isnt worth twice the price but I said what the hell and pulled the trigger. No more than I upgrade I figured I could splurge a little and be safe. Heck the wife may not give me the go ahead to do any upgrades for another 4 yrs so I have to get the bells and whistles when I can lmao!

Post by **FlyingPenguin** » Thu Feb 26, 2009 8:55 am

Ahh okay. Yeah, the modular cabling is nice and that's a good chunk of the price right there.