Which PSU?

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JDCentral

Senior member
Jul 14, 2004
372
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....

What happens if I am an electrical engineer?

hehe.

Granted, I like your style... But ALL these PSUs are great, and are all w/in a $10 price range.
EDIT: sorry.. can't think of anything else more to say. not sure where I was going...
 

dwcal

Senior member
Jul 21, 2004
765
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Originally posted by: JDCentral
Also... just for reference, dwcal - what are your system specs?

Still under construction, but so far it has:

A8N-E, 3200 Venice, X700 Pro, 1 7200rpm HD, 1 DVD burner, 2 low speed 80mm case fans, and the retail HSF.

I've had the CPU up to 2.31Ghz and the X700 Pro up to 462/950. The 20 pin ATX connector is no problem. I'll probably add on a firewire card to charge the iPod, a CDROM drive to save wear and tear on the DVD burner and a 2nd hard drive. I'll let you know how that goes. I don't plan on running a high-end video card, so the SS300 looked like plenty of power for me.
 

Zepper

Elite Member
May 1, 2001
18,998
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The PSU you need depends on whether your mobo runs the CPU off the +12 or the +5. If your mobo has the P4-12V connector (4-pin square) then it runs CPU off the +12 so your PSU needs to weight its output more heavily to the +12 - if no P4 connector on your mobo, then you need to have an old style PSU with power heavily weighted to the +5. It's really just that simple.
. It has to be a REALLY GOOD deal for me to ever buy a mobo w/o the P4 connector. I've seen enough melted ATX connectors due to very high current on the +5 to last me the rest of my life. Plus the load on the PSU is much more balanced. My Abit KW7 is Sock-A and has the P4 connector, most MSI Sock-A have it, etc.
. After that, there is the issue of other +12 sucking devices like some of the new vid cards - and/or a large number of HDs then you need to go even more to the +12.
. Sparkle 350 is a good choice for older style mobos and vid cards with a typical number of drives. Should run in the sweet spot of its efficiency curve.

.bh.
 

JDCentral

Senior member
Jul 14, 2004
372
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Zepper-

That was EXTREMELY helpful... I have been getting a lot of mixed information about the 5V vs. 12V rails. Most just said that if it was an 'older' mobo, it ran off the 5V rails.

my mobo says that it runs off of the 20-pin ATX Power connector - I'm assuming that this is the older-style w/o the 4-pin P4 connector.
 

Zepper

Elite Member
May 1, 2001
18,998
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Asus does a better job on it's mobo power regulation as it uses a 3-phase system which helps justify the higher cost of an Asus mobo. But they could get at least as good a result and at a lower cost if they would just give it up and go to the +12 rail w/ 2-phase regulation. (You'll note what they went with on their excellent Asrock "budget" line of mobos)...
. IAC, you are right. As you will note, there is only ONE +12 wire in the 20-pin ATX and only one more in the 24-pin EATX - also that there are 5 +5 wires (6 on the 24-pin). So if you're powering the CPU(s) (as well as whatever other +12 needs a mobo or add-on cards may need) from the +12, there has to be an aux connector - either the 2x2 for single proc. or the 2x4 for dual proc. And there is yet another connector if the vid card needs extra +12 either on the card itself or the special SLI connector on SLI mobos.

.bh.
 

dwcal

Senior member
Jul 21, 2004
765
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Originally posted by: JDCentral
my mobo says that it runs off of the 20-pin ATX Power connector - I'm assuming that this is the older-style w/o the 4-pin P4 connector.

Not exactly. The extra 4 pins on a 24 pin ATX connector are for the PCI Express slots, and they're all together in the ATX connector. The square 4 pin P4 connector is off by itself. A power supply can have a 20 pin ATX connector and a 4 pin P4 connector. You have to go even older to find a PS without the P4 connector.
 

Susquehannock

Member
Nov 18, 2004
114
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Originally posted by: Zepper
The PSU you need depends on whether your mobo runs the CPU off the +12 or the +5. If your mobo has the P4-12V connector

Kudos! Was waiting for that. The ASUS a7n8x does indeed power the CPU from the +5v rail.
I've worked with a few and they are nice boards. Poor overclockers for the
most part, but for a stable stock system it's an excellent choice.

Fortron PSU ....

I've used several of those and they are very good. ducci was spot on about the efficiency
and amperage specifications being mostly crap. They are just marketing tools since there
is little standardization.

I've had a couple 300w Fortron PSU that would easily outperform 550w generic units in'
the exact same set up.
Like I always say - Quality over Quantity!