Novice building desktop needs PSU advice (how many Watts do I need?)

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DCNZ

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Wannabe Geek

#54716 19-Dec-2009 10:41

Hi,
I am a complete novice & i'm building a PC from scratch...

MOTHERBOARD: Gigabyte 6vtx
PROCESSER: Pentium III-S 1.4GHz, 1.45v, 133FSB, Socket 370, SL6BY, Tualatin
RAM: 512mb SDRAM pc133 (x3)
SOUND CARD: CT4830 Sound Blaster Live!
TV TUNER CARD: PCI Slot (unknowen brand yet, still coming in the mail)
GRAPHICS CARD: Winfast GeForce Ti4600 A250 Ultra TD
PCI USB2 (x4+1)
IDE 80GB (2x40GB) HDD
DVD-RAM & CD-ROM
FDD
KEYBOARD & MOUSE
(all this for starters)

*My question is, Can I run all this on a std 150watt PSU or will I need 300watts?
If I use one 150W PSU to run my motherboard & another 150W PSU to run my HDD's & FDD dose that give me 300watts or is it the motherboard thats going to need one 300w PSU?
Thanks,
Daniel.

xpd

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#284016 19-Dec-2009 14:39

Get a 300W minimum single PSU - using 2 150's will work but requires you to jump the 2nd PSU to get it powering up and have room for it and a 2ndary power cable. (or make a switch for it)

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sbiddle

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#284017 19-Dec-2009 14:43

With 3 cards, 2 HDD and the 2 optical drives you'll definately need to go with a 300W supply.

Having two power supplies is a strange idea and very impractical.

DCNZ

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Wannabe Geek

#284059 19-Dec-2009 18:14

sbiddle: With 3 cards, 2 HDD and the 2 optical drives you'll definately need to go with a 300W supply.

Having two power supplies is a strange idea and very impractical.

I was just hoping I wouldn't have to fork out any more money to get this thing running. I already have 2x150w PSU's but i'll have to buy a 300w one if I can't bridge them & I thought two 150w's might run cooler, but hay, if it's not possible then its not possible.

Thanks anyway.

sbiddle

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#284064 19-Dec-2009 19:39

How did you plan to switch the 2nd power supply on? You'd have to rewire it for it to switch on - a normal PSU won't power on until the on/off button hooked to the motherboard is turned on. It will not normally provide +12v until then but some PSU's will provide +5v without being turned on.

If you didn't want to run so much a 150W supply would be plenty just for a mobo and HDD, but dual optical drives, dual HDD's and 3 PC cards all suck a lot of power.

DCNZ

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Wannabe Geek

#284108 19-Dec-2009 23:26

sbiddle: How did you plan to switch the 2nd power supply on? You'd have to rewire it for it to switch on - a normal PSU won't power on until the on/off button hooked to the motherboard is turned on. It will not normally provide +12v until then but some PSU's will provide +5v without being turned on.

If you didn't want to run so much a 150W supply would be plenty just for a mobo and HDD, but dual optical drives, dual HDD's and 3 PC cards all suck a lot of power.

I have no problem with wireing. I just wanted to know if I would be doubleing the amps & volts if I did :) Thought I might be able to run HDD's FDD's & DVD's off one & the mobo off the other.
What i'm trying to find out is why I need so much power, basicly my question should have been how much power dose the mobo drain. I have decided to run the mobo off a 300w+ PSU & everything else off a 150w PSU.
Thanks mate, everyone in the chat room has been a great help to.
Daniel.

DCNZ

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Wannabe Geek

#284114 19-Dec-2009 23:58

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----------------UPDATE--------------------------------------------------------------------------------------------

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I have now brought a brand new 420w ATX PSU to run the mobo & i'l use a 150w PSU for the HDD's, FDD's, DVD-RAM's, LED's, etc...
Thanks for all your responces,
Daniel.

sbiddle

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#284131 20-Dec-2009 08:31

A 420W power supply would be sufficnent for everything, why do you still want to run 2 different power supplies? I'm assuming the 2nd power supply would not be mounted inside the case? This should not really be done under NZ electrical regulations - they are not designed to be an external power supply.

One thing you also haven't addressed is how you plan to actually make the 2nd power supply work. Is this a model that will provide +12v and +5v without the motherboard power connector connected or are you going to hack it so it will work?

vinnieg

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#284157 20-Dec-2009 11:19

Not too sure why you still want to run 2 PSUs. You'll have to use pin 4(green and any of the black wires and wire them upto a switch). but it means you won't be able to put any discs to sleep unless you had a physical switch wired to each one.

http://www.burningissues.net/how_to/power/psu.htm - simple switch method

http://www.speedy3d.com/articles/case_mod_p3/01.shtml - relay method

Imo...it's more than likely you'll end up screwing up one or both PSUs, leaving yourself to fork out money for another one. stick to one, the HDDs, LEDs, DVDs, Cold cathods and watercooling or whatever you want to throw at it all require 12v DC. Which on a 420w PSU you should have at least 1-2 rails with plenty of Amps

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