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Crappy power supply is crappy

Discussion in 'Cases, Modding & Electronics' started by Necrofire, Nov 1, 2007.

  1. Necrofire

    Necrofire New Member

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    I need a new one, but I was actually googling an alternative to a whole new and expensive power supply.

    I want to run two power supplies at once for one system, and I just had a couple of questions.

    1. According to some places, I can just put both PS-ON wires together and two grounds and call it good, would that work with two different power supplies?

    2. Would anything detrimental come about from powering a graphics card from one power supply and everything else from the other?

    3. Is wiring grounds together (like in #1) a bad idea?

    4. Would slightly-different voltages between the two power supplies cause something to go wrong? (i.e. let's say that graphics card is taking in 12.025V and mobo is taking in 11.995, will there be problems?)

    Here's rig:

    athlon x2 6000+, OC'd to 3.2GHz
    2GB ddr-800
    3 Harddrives
    1 DVD drive
    Nvidia 8800GTS Overclocked (slightly)
    Biostar Nforce4-Ultra
    Hauppage TV tuner

    My main power supply is 450Watt, not the advertised 575W, the latter is the max rating, and the first is sustained. It was less than $40, so it's crappy as hell.

    The second power supply is a 350Watt Cooler Master, and it's pretty old.

    My main power supply puts out 25A on +12Volt, and the second one puts out 16A on the +12Volt rail.
     
  2. AsRock

    AsRock TPU addict

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    Well some power supplys will not even turn and some really old ones will blow a fuse when the 20 pin is not connected. I'm on about old ones now as i'm not sure about todays but chances are they turn off.

    Never tryed by passing it my self.


    You be better of getting a $100+ power supply anyways as those cheap ones can mess your rig up.
     
  3. panchoman

    panchoman Sold my stars!

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    you can pair em up, you'll need a relay switch and it'll work, and space for the psu's as well. the voltages wont really be a problem.

    oh and welcome to the forums :)
     
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  4. DR.Death

    DR.Death New Member

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    y not just buy one big psu it would be less hassle and then less can go wrong
     
  5. panchoman

    panchoman Sold my stars!

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    yup, and of course you can get some really nice and efficent psu's now.
     
  6. zekrahminator

    zekrahminator McLovin

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    I'd get a $40 Thermaltake PurePower 430W for mobo/peripherals, and a $60 Thermaltake VGA Power Supply. Your $100 will get you all the power you need for a long time, as well as all the adapters you need to make that happen.

    Or, if you were to reconsider and get a single-PSU solution, I'd get a Mushkin power supply, or if you can spring for it, a Corsair :).
     
  7. panchoman

    panchoman Sold my stars!

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    i vote corsair..
     
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  8. Necrofire

    Necrofire New Member

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    Thanks for welcoming me.:respect: I'm glad to see that I'm actually getting answers. The problem with getting a new power supply is money. I don't exactly have $80 or so laying around. Then what would I do with the power supply I have now? It works, but not well.

    The Graphics card power supply isn't worth it, and I couldn't upgrade the graphics card. According to my sources, the 8600GTS can pull ~200W or so on a full load.

    On the topic of graphics card power supplies...If I can run a separate dedicated power supply for the graphics card, what would be the problem of making my second power supply into that dedicated supply?

    That Corsair has nice specs, but costs more than I'm willing to spend.

    The Thermaltake 450W is worse than mine. I was thinking that I need more amps on the +12V rail, since mine puts out 25A total, and the Thermaltake only puts out 18A. I would need two rails putting 18A or so out a piece.

    If mixing power stuff is as dangerous as I've been seeing, then would it be better to run harddrives and fans with the second power supply, so that I could maybe take 50W of load off or something?

    My biggest problem is heat from the power supply. It gets really hot, leading me to believe that it's being worked too hard, or HIGHLY inefficient. I can wait for a solution if need be, but I want a solution that involves two power supplies at the least, since it is what I have to work with right now.

    I understand what volts and amps are, and have a basic understanding of how power supplies work. What I don't know is what happens when you try and put power supplies in parallel, or the detriments of putting grounds together, or the problems that would arise if the power supplies were vastly different in startup time or voltage under load.
     
  9. zekrahminator

    zekrahminator McLovin

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    Then you should definitely take out a loan or something, because you're not going to get stable, reliable results from anything less than something with a little oomph in the 12V+ department.
     
  10. DR.Death

    DR.Death New Member

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    ya a new psu would be the best bet for now because with 2 of them u never know what will happen down the road
     
  11. zekrahminator

    zekrahminator McLovin

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    Here's something that I'd expect to last a while...

    FSP 450W PSU (2x18A on the 12V+).
     
  12. DR.Death

    DR.Death New Member

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    or look what antec has to offer
     
  13. Necrofire

    Necrofire New Member

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    Wow, that's exactly what I've been looking for, but I've never heard of the company. Will this be enough though?

    EDIT: Strange, I clicked the right quote button, but it turned out the wrong quote, eh.
     
  14. zekrahminator

    zekrahminator McLovin

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    Oh yeah ;).
     
  15. panchoman

    panchoman Sold my stars!

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    fsp's a great oem, and they sell their own psu's as well, i'd say grab that psu.
     
  16. Necrofire

    Necrofire New Member

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    It looks interesting, I think it will suffice. I don't exactly have 2 8800 Ultras I need to power. The efficiency is a little low for what I'm looking for, but 80+ ones are expensive.

    Most of my system was built using Newegg, including my current power supply...

    But really, I need a definitive, highly technical answer for the dual-power supply thing. Is it viable?

    On another subject, though, my second computer was beat down by a short on 12V line repeatedly. Do you guys know the likely culprit that died? The short was the P4 connector on the mother board, I think. Power supply still works, and I *think it's the mobo.
     
  17. patton45

    patton45

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    The egg has a pc p&c has a 40$ psu its the best cheap option
     
  18. niko084

    niko084

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    You "can" do that... But make sure you wire it right.
     
  19. DrunkenMafia

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    mate you are playing with fire though.. I mean you have some expensive parts in there and when psu's die they can often take out other components with them...

    Just fork out the $80 or so bucks and grab a decent one.. You may even be able to buy a second hand decent one on ebay.. A lot of junkies upgrade all the time..

    Here is a brand new antec eartthwatts 500w . Removed from a new case for $49... Thats not bad and will be good enough to power your system..

    http://cgi.ebay.com/Antec-EARTHWATT...ryZ42021QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
     
  20. niko084

    niko084

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    Just to second this-
    Earth Watts 500 is the same as my Smart Power 2 450 in one of my machines..
    I have put a 1950pro, and now a heavily clocked 2600xt and e6750 on it, doesn't even get warm :)
     
  21. Mussels

    Mussels Moderprator Staff Member

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    pretty much yes to all your questions.

    Most people use two PSU's, and have the second for fans/cooling - you CAN have issues if the voltages go different, for exampel - video cards use power from the mobo and a secondary lead, so you dont really want to mix them up and have two sets of different voltages going in there.

    merging grounds would help i think, but i personally wouldnt do it.
     
  22. Necrofire

    Necrofire New Member

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    You guys are great, I used to frequent TechPowerup for the reviews and stuff, but never ventured to the forums. This is the first place I've had so many people answering so fast..

    Anyway, I have a test rig that I can test my "new" idea on. Until I get some money for a better power supply, I'm going to do the following...

    1. Wire both PS-ON wires together, and two grounds together. It seems like this power supply has no problem doing so. (just look at the 4th and 5th images)

    2. Instead, I'm just going to take the load off from the harddrives and fans, which would be around 50 Watts or so.

    3. Test this on my test rig before hand, I don't care if I kill the rig, since something in it is already dead. (The 12V line shorted somewhere after I put a new heatsink on (sounds weird) and after I reseated the heatsink a couple of times, it would turn on, and nothing else. (too bad I don't have a speaker lying around anywhere))

    4. If it works, hook it up to my current rig. I don't use my DVD drive AT ALL anymore, so I was just thinking of taking it out, and mounting the power supply in the 4-bay gap.

    btw, Since the fan would be facing outward blowing air out the front, I'm going to invert the fan so it blows in.

    5. Take pics if anyone wants to see my rig, either before or after. 1.3MP Phone camera, with plenty of lighting...(It gets the job done, I think)

    6.???

    7. PROFIT!!!
     
  23. JrRacinFan

    JrRacinFan Served 5k and counting ...

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    If you plan on doing this make sure you use a UPS. Also, just one small tip because I HAVE done this before.

    Let's call the power supply that powers the motherboard, the master psu, and the other the slave psu.

    The master psu you will have to make sure it is screwed tightly onto your pc case and make sure their are no obstructions for any wires at all.

    The slave psu is usually best mounted on the bottom of a full size ATX case in conjunction with use of an mATX motherboard.

    As far as how to wire them together, pins 14 & 15 do the trick.
     
  24. keakar

    keakar

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    when its all said and done your going to spend damn near the same $ to get 2 psu and the switches you need and wire them up, then you have the timing of both coming on and going off at the same time is also a risk of not being right plus you have to take into account all the wiring involved are always a risk to fail and when that happens bad things can occur.

    one good high quality power supply = no troubles cost $100-$150

    two power supplies = lots of things can go wrong and screw up your system plus you spend the same $ (this way would cost about $100-$150) as if you would just buy 1 good quality psu with enough amps to serve your needs.

    its always better to use one psu instead of two as long as you can get all the power you require from that one psu.
     
  25. Wile E

    Wile E Power User

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