Question for the Gurus

Hi there,
So I decided to build myself a new P4 system and during my research on this board realised that I had totally overlooked the PSU. I am trying to find a quiet PSU that has enough juice to handle a P4 sytem with the "Extreme Edition" CPU, running on an 875p mobo, 9600xt card, WD360 Raptor SATA HDD 10000rpm)

After reading all 20+ pages of posts (so I have done my research) I still have a few questions:

1. What makes a PSU SATA compatible? (I will be getting an SATA HDD).
2. a)I know that Fortron, Enermax and Zalman are highly recommended. However in trying to do a comparison of the 3 I am a little confused about the output for each of the 3 rails.
If Zalman output is +3.3V=28 +5.5V=40 +12V=18
Fortron output is +3.3V= 32 +5.5V=40 +12V=24
which is better? Is more better? which is the more important rail (which systems use which rail?)
b)I read somewhere that with the P4 systems the 12V rail is most important? True?
c) do I need a dual 12v rail? why? (does Fortron offer this)

3. I was going to get the MSI 875P Neo(or 865PE Neo2-FIS2R) mobo and noticed that front USB was only supported via "pin out". Since I am going to get a case with front USB ports can anyone explain to me what a "pin out" is?
The other mobo I was considering was the Gigabyte GA-8KNXP and this has front USB support without need for a "pin out"?
Confusing ......

Hope you can answer some of my questions.
btw it'd be great if some of my questions are incorporated in the FAQ (I'm sure other newbies have similar concerns).
5 answers Last reply
More about question gurus
  1. 1.) Some power supplies have SATA power headers, which have a 3.3v line. Others don't. Most SATA drives accept either type of header (old style or SATA power). And most boards come with SATA power to 4-pin adapters. So any way you look at it, there's no need to worry.

    2. a) I'd love to give you a definative answer, the problem is that everyone rates their supplies differently. Since Fortron rates their supplies at 70% peak, a Fortron that says 14A on the line should output as much as an Enermax that says 20A. Etc. Just buy a good quality supply and don't worry about it.
    b) True
    c) My P4 2.6C ran fine at 3250MHz, with 2 hard drives, a bunch of SCSI drives, a SCSI controller, modem AIW 9600 Pro video card (highly overclocked), 1024MB of PC4000 at 2.85v, etc, producing huge heat (and therefore consuming huge power), on a Fortron 350W power supply. If you buy the 400W, it's overkill for most high end systems.

    3.) Pin-Out is the header the cables for front USB uses. LOL on the gigabyte board discription, there is only 1 way to connect the front USB ports to the motherboard, and that's using cables to pins on the motherboard.

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  2. Before i get into answering you questions...let me just say you have a pretty "lopsided system" i mean you have a $1000 cpu, the fastest ATA hard drive around and a mid range video just seems silly to me...

    1. SATA hard drives use a diffrent connector than standard ata hard drives use...many mobos come with molex (old style) to sata adapters.
    2. A. A higher amperage is better...the 12v and 5v are among the most important but major fluctuations in any rail excluding maybe the -5v and -12v are bad for stability.
    B. It depends on the motherboard diffrent mobos take the cpu voltage from diffrent days i beleive most mobos DO use the 12v rail to power the voltage regulators and thus the yes that is a true statement for the most part.
    C. I am 90% sure fortrons high end psus offer this, although i think this is MAJOR overkill for any single cpu mainboard, however i beleive it is to allow the hard drives, cdrom drives etc to run a diffrent rail than the mobo is using so that diffrent amounts of load will not cause their voltage to fluctuate...
    3. I beleive this refers to the motherboard using a special connector for the internal usb ports...most cases and all mobos i have seen take advantage of this..basically it carries all of the signals that a standard usb port does just it has a diffrent pinout and connector style.

    I would recomend that you take a look at epox's 4pca3+ mainboard which i found to be a very nice motherboard in both price and features (it includes ata to sata power converts btw). Also the latest fortron psu that i have delt with did have the sata power connectors. I personally would recomend a 350-400w fortron powersupply for your system. If for some daft reason you would like to spend more on an inferior psu from another brand look on the order of +400w.

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy
  3. damn u beat me!

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy
  4. Thanks for the help guys really appreciate it, and you gave me a good education.
    Based on what I have read here and the reviews on the site I have narrowed it down to:

    - Fortron Source 400W
    - Zalman 400W

    I'll go with whichever one is cheaper.
    Thanks again!
  5. Why are you spending $1000 on a processor and looking for the least expensive PSU? Seems nutty to me! The P4EE is really a waste of extra money for very little performance increase. If that's really want you want I wont argue with you, but I think if you really look into it, you'll find that you can get a comparable level of performance from a much less expensive CPU. (I guess it sort of depends on what you're doing with this computer too).
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