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What is a good single +12v rail amp value?

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January 4, 2008 6:46:17 PM

Hi all,

I'm about to buy a STRICTLY budgeted PSU soon ($19-25 USD only). ATM, I found 3 choices in egg:

my 1st choice:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

2nd:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

3rd:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

All of them are Single rail PSUs. I don't want 2 rails .. I dont need it.

Now there reason I picked the first one as my 1st choice is because it has a good amout of amps in +12V rail.

It has +12@28A .. the other choices has lower.

What is a good or highly recommendable amount of amps for a +12v rail? SHould it be over 30A, 35A?

I'm also confused of the +5V which has high amounts of A? Where are those +5V used for inside the PC?


If you could recommend me a good one that is not listed on my links, please do so. Please note that it should only be $19-25 (I don't go for MIR because I have to go back to my home country soon, I wont get my MIR anymore)


BTW, these are my specs:

E2180 (with stock hsf)
GA-P35-DS3L
Inno 3d - 8500GT gfx (I know its crappy, but I bought it already and it seems fine :D )
(1) 80gb western digital hdd SATA
(1) 80gb Maxtor IDE
(1) Lite-on 20x DVDburner SATA

No other PCI or PCI-E components connected
Not overclocked (maybe I will, 6 months from now)

Thank you so much!
January 4, 2008 8:41:34 PM

im sorry to say that these are all some of the worst psu's out there, really and truely you would be better off just waiting and saving the pennies because when that cheap psu burns up in a month youll be out 25 bones and youll have to get another one
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a b ) Power supply
January 5, 2008 4:25:32 PM

I'd go for the thermaltake. I like fortron fsp, but the 400w model is about $50 shipped, which is over your budget.
January 5, 2008 6:19:52 PM

Yup, 50 is too much for me :(  But, I think ill go for the Thermaltake as well .. however, its kinda weird that it only has 18A under +12V .. I think I dont understand power supplies that much .. but according to some reviews, it is always wise to pick a power supply that has morethan 30A in +12v rail.

This is the thermal take output info: (you can also find this under specifications on the link posted above from newegg):

+3.3V@20A, +5V@30A, +12V@18A, -5V@0.5A, -12V@0.8A, +5VSB@2A

Can someone who knows the real deal with PSUs why it only has 18A?

THe other one, Cooler Master dual rail, has 2 rails of +12V and both have 18A

kinda confused :( 
January 5, 2008 6:49:32 PM

That thermaltake is a bad-a lil PSU...I've owned about 4 now...what i used on my first build that ran a 4200+X2, 2gb ram, x1900GT; replacement for my dad's comp; on my dad's business comp; my friends semi-gaming rig (amd 4200+, 7600GT, 1xHD, 1xDVDRW, 1gb ddr2) and friend's g/f's comp...one has been running for 2 years strong now...i highly recommend it
January 5, 2008 7:09:26 PM

rosecityotters said:
That thermaltake is a bad-a lil PSU...I've owned about 4 now...what i used on my first build that ran a 4200+X2, 2gb ram, x1900GT; replacement for my dad's comp; on my dad's business comp; my friends semi-gaming rig (amd 4200+, 7600GT, 1xHD, 1xDVDRW, 1gb ddr2) and friend's g/f's comp...one has been running for 2 years strong now...i highly recommend it


Wow :D  Thanks for you reply.

Did you try overclocking? Just minor overclocking?

Thanks again.
January 5, 2008 7:57:35 PM

The video card you are using only takes 4A max from 12V supply. The problem is that cheap cr@ppy PSUs lie about their ratings. If you read the spec carefully, sometimes it is PEAK power, not max continuous. Many cheap PSUs struggle to give 75% output for any reasonable time.

Mike.
January 5, 2008 8:20:56 PM

IMO, the PSU is the last place to "cheap-out", as it provides power for all of the components in the system. A crummy PSU can result in unstable operation, or even damage the other components if it fails. Like everything in consumer electronics, the PSUs are made as absolutely cheaply as they can be. If you are paying $25 for the PSU, it probably cost the MFR around $5-$8 in parts. Sounds scary to me!

FWIW, the single +12V rail is the way to go, even for larger power supplies. Ideally, a PSU having multiple 12V rails should have the loading on each of the rails balanced. It is always difficult to balance things perfectly, and it is also likely that some of the supply's capacity will lie untapped. The single +12V rail design eliminates these issues. I chose the PC Power & Cooling Silencer 750 Quad for this reason (60A on the 12V rail).

EDIT: FYI, I am an electronic design engineer with more than a little experience in this area. . .
January 5, 2008 8:45:13 PM

Newegg has a SeaSonic 330W recertified power supply that has 22Amps across 2 +12v rails for $40 with free shipping or a SilverStone 350W with 25Amps across 2 +12v rails for $40 with free shipping and a $10 mail-in-rebate. Both power supplies are good quality, with SeaSonic being a great manufacturer(nothing below Tier 3, most PSUs in Tier 2) and the SilverStone being made with a Tier 3 FSP PSU.
!