external power supply for v-card

By jjkahler
Jul 26, 2002
Topic Status:
Not open for further replies.
  1. Hi, I am new to these forums. Was hoping to get some advice on using another power supply for a new vid card that i got. The vid card recommends that I have a 350 watt power supply, but mine is only 200. I do have another power supply from an older computer just laying around, but that is also only 200. Is there a way to use that also? Even if it does sit on the outside of my cpu it doesnt matter. I dont have a really fast comp, old P3 400, so my budget is very tight. (thus reusing existing parts) Any help is appreciated. THX
  2. StormBringer

    StormBringer Newcomer, in training Posts: 2,871

    What Video Card are you talking about? It may be a bit much for that system, you might want to get something a little more matched to the system.

    There is a way to do this but it is a little different than you are talking about. The best way would be to use the other PSU to power things like Drives and fans. Those devices can use the connectors already on the PSU. This may work if you can divert enough power to the second PSU so there is enough power left for the other devices and the Video card.

    This could be very easy to do, or it could be very difficult. According to your level of electronics experience as well as the particular PSUs you have. Some PSUs will only power on if the mobo connector is attached(which can be circumvented)

    You'll also need a way to turn both PSUs on at the same time which is not too difficult either.
  3. jjkahler

    jjkahler Newcomer, in training Topic Starter

    thx for the info, i am pretty skilled in electronics, so adding a pigtail or something of that nature is not a problem.

    I would have prolly been better off going with a lesser video card, but I will be buying a new set up in the near future, so I didnt want to be too cheap on the video card I just got, Geo 420.

    My system is a Dell XPS T450 General System Information
    Computer Model Dell Dimension XPS T450

    BIOS Vendor Intel Corp.
    BIOS Version A04
    BIOS Date 04/22/1999
    Case Type Unknown
    Windows Version 98
    Explorer Version 5.00.2919.6307

    Processors
    Central Processor
    Manufacturer Intel Corporation
    Product Name Pentium III processor
    Version Intel Pentium(R) III Processor
    External Clock Speed 100 Hz
    Maximum Clock Speed 500 Hz
    Current Clock Speed 450 Hz


    Memory
    System memory with 3 slots - Placement: System board or motherboard
    DIMM: 128 Mb DRAM
    DIMM: 128 Mb DRAM
    DIMM: empty

    Windows Memory/Resources
    Total Memory 261648 Kb
    Available Memory 1840 Kb
    Page File Size 1835500 Kb
    Available Page File 1758336 Kb
    Virtual Memory 2093056 Kb
    Available Virtual Memory 2017728 Kb


    Hardware (Built Into System)
    Type Description Enabled
    Video AGP Yes
    Sound AUDIO Yes
    Sound AUDIO Yes
    Sound AUDIO Yes

    Hardware (Added On To System)
    Type Description Manufacturer


    Disks
    Drive Type Drive Size Total
    Available
    Space User
    Available
    Space
    A:\ removable
    C:\ fixed 6137 Mb 2130 Mb 2130 Mb
    D:\ CD ROM 631 Mb 0 Mb 0 Mb


    So, any other recommendations on video card for this system is much appreciated (right now some games like WC3 is pretty choppy even at 640x480). I know the Geoforce 4-420 is a little much, but again I will be upgrading to a new computer in the near future.

    Any problems that are forseen with adding a power supply just for the vid card would be much appreciated ( besides what Stormbringer has said).

    Also I am using this comp just for gaming. (I know, I know, this comp sucks for gaming right now, but slowly I will have a new one).
  4. Mictlantecuhtli

    Mictlantecuhtli TechSpot Evangelist Posts: 4,916   +9

    :approve:
  5. uncleel

    uncleel Newcomer, in training Posts: 1,145

    Watts required is the sum of the total, but 200w is pretty weak given modern system requirements. This should answer all your questions.
    Other Hardware > Power Supply Concerns . . .
    http://www.techspot.com/vb/showthread.php?s=&threadid=377

    This has been discussed quite a bit before.
    to determine PSU requirements

    From the old forum-->
    Famous PSU Post

    most recently-->
    http://www.3dspotlight.com/vb/showthread.php?s=&threadid=253

    related subject-->
    http://www.3dspotlight.com/vb/showthread.php?s=&threadid=375

    It's best just to buy a quality PSU rather than add another just for the vid card.
    P.S. Please enable Private Messages
  6. StormBringer

    StormBringer Newcomer, in training Posts: 2,871

    Uncleel, it would be completely moronic to buy a new PSU, seeing as he already has another 200W. Besides he said he is strapped for cash. Adding the additional PSU is a very viable option. It is a simple thing to use the two in tandem.

    (*edited by mod)
  7. Rick

    Rick TechSpot Staff Posts: 6,304   +52 Staff Member

    It won't be very pretty, but you can plug in the other PSU and if you can find somewhere to sit it, you can run the power cables inside of your case and use them.

    This could be a temporary solution until you get a better PSU (if you need one).

    Chances are, depending on your equipment, your PSU is probably capable of carrying the proper load since your system is pretty old. I know 200 watts back then was fairly common, and 250 was considered quite a bit.

    If you have any problems though, getting a new PSU (if you do indeed need one) is fairly cheap. You can get a 300 to 350 watt for less than $25 USD pretty easily. Name brands usually cost more though.
  8. uncleel

    uncleel Newcomer, in training Posts: 1,145

    Re: external power supply

    1st Determine your power supply requirements. Consider safety issues, such as having another PSU laying on the floor, ungrounded, [chassis] w/ wire hanging out everywhere? If you can afford a GeF4, then borrow 25 -to- 35 bucks & get a generic 300w to you can afford the $89 to buy a quality one.
  9. StormBringer

    StormBringer Newcomer, in training Posts: 2,871

    And this differs from the PSU in your case already how? You do realize that the only ground in your computer is on the power cord attached to the PSU right?

    There is also a good chance that he could fit a second PSU into his case if there is room which would eliminate any wires hanging out.
  10. uncleel

    uncleel Newcomer, in training Posts: 1,145

    Re: external power supply

    chassis ground -vs- earth ground; & when you trip over it, ( or someone else in the family) you become the ground.

    Trust me... No repair shop would perform this fix.
    I don't believe in advocating this type of fix concidering the trouble, problems, & lack of safety associated w/ trying to run two psu's. This is PIII-450MHz rig in a mid-tower case.

    Spend a few buck$ & you are way ahead.
    Electroseller.com
  11. StormBringer

    StormBringer Newcomer, in training Posts: 2,871

    A chasis ground is only a common reference point in relation to the opposing current. The Earth ground is the only true ground.
    There is no difference between the PSU and the computer case in respect to ground because they both have power cords that are grounded.

    As I said, he should have room in the case to fit the other PSU. He says he is experienced with electronics. If the PSU won't fit into the case, it can easily be attached to the top of the case and the cables can easily be run into it without too much trouble. It doesn't take an engineer to figure out how to safely perform this modification and still make it look presentable.
  12. uncleel

    uncleel Newcomer, in training Posts: 1,145

    Re: external power supply

    The issue is that most of our readers are not electricans & we should not be advocating anything less than correct "shop" procedure. Less lil' jonnie decides to try this trick @ home.

    Regardless of "ground" theory, building & industrial codes go for the extra edge of safety.Have you ever seen electric motors & machinery in an industial application? Or a swimming pool pump & motor? Regardless of the "ground" wire, they are "strap" grounded on their respective platforms. Pools are grounded to a 8' copper grounding rod, driven into the ground. Would you use a third wire grounded tool in a pool? Why not? It's grounded! Tell that "ground" theory to the dead guy.

    That is the difference between a psu attached to the computer case -or- lying on the floor in respect to ground, regardless if the power cords that are third wire (grounded.) And the difference is Safety!

    I disagree. Spend $20 for a psu rather than having a Bride of Frankenstein mod.
  13. StormBringer

    StormBringer Newcomer, in training Posts: 2,871

    I was right before. Editing my post doesn't change that.

    Your argument has no basis because the PSU is not grounded to the computer, rather the other way around. You no nothing of electrical or electronics do you? I do, it is my job. Most of the places I do repair work for have very little to work with and I must improvise just like this on a daily basis. I have to "rig" things but I also have to keep safety first. Thew repairs must always be able to pass OSHA and ANSI inspection.

    This mod is no more dangerous than changing a PSU.

    Oh, and about the 8' grounding rod on a pool, Your house is also grounded to one. That is the standard earth ground that everyone is always talking about. Most structures have one whether there is electricity used there or not. At least that is what local building code here dictates.
     
  14. Rick

    Rick TechSpot Staff Posts: 6,304   +52 Staff Member

    I don't think anyone is getting shocked her unless they grab ahold of a capacitator or something... The PSU does not spew sparks and melt wires in the case, and I'm fairly certain it won't outside of the case either. And unlikely as it may be, there may even be room enough in the case to have two PSUs.

    As far as hazards go, this isn't any more dangerous than building your own computer and far more safe than some of the monitor modifications we've had.

    I agree with this myself. I'd rather just buy a better PSU than use two at a time, but we'll leave that up to jjkahler to decide.

    The fellow said he's skilled in electronics work, so this isn't a bad option to explore. He's already got the parts necessary and it will save him twenty to thirty bucks. If he has the know how and parts, then is this not a valid suggestion? :confused:

    I don't understand these "grounding theories" too much. But if the third wire in the PSU has a purpose, it's connected to the houses's grounding pole, which is an 6' to 10' metal rod embedded in the foundation of the house. The main purpose of grounding is for lightning though, isn't it?

    Regardless of grounding, you'll get shocked all to hell anyway. ;) I think that's been proving over and over again.. even by myself. hehe! :blackeye:

    Just be careful jj and don't touch anything you shouldn't. :eek: I think this sounds like a worthwhile idea.
  15. uncleel

    uncleel Newcomer, in training Posts: 1,145

    Re: external power supply

    In theory, if you are properly grounded, then use a power tool while standing in water. Other than the "theory" classes; ( I was in college when you were 2 yrs old) real world practical working knowledge & safety is the key issue when you are out in the field & earning a living.

    Electricity takes the least path of resistance.

    No matter how you are grounded, you become the ground. Mr. Fork does not play w/ Mr. WallSocket.

    1.) Though the postee may have some electrical skill, this is not a job for the average member.

    2.) A skilled person would logically consider just putting in a psu rather than waste time modding it.

    3.) You should not advocate this mod to the less skilled.
  16. StormBringer

    StormBringer Newcomer, in training Posts: 2,871

    ground has very little to do with this, the point I was making was that the case of the PSU doesn't differ from the case of the PC because their grounds are the same, that of the power cord. The only danger in this is if you left the wires hanging all around or in the middle of the floor. Doing that would be stupid anyway.

    Whatever you say Uncleel, I'm tired of arguing with you about this. You obviously don't understand anything I'm trying to tell you. I've only been working with electricity and electronics for eleven years, so maybe I don't have enough expertise in the field to know what I'm talking about.
  17. uncleel

    uncleel Newcomer, in training Posts: 1,145

    Re: external power supply

    This is not an argument, sorry you have that mindset.
    This is a safety issue.
    This is about a mod that the average member should not be attempting. We also have liability issues.

    We have gone from from:
    • attaching a "external" power supply
    • placing the psu on top of the case
    • installing inside the case

    And you would agree, regardless if you using a grounded plug to the psu, accidents happen. Stupid accidents happen. This is not a mod for the average member, but I'm glad you are skilled. This is not a dis' of you personally nor of your respective profession or experience in your field. But accidents happen everyday from the "less than skilled." TechSpot members should have a healthy respect for eletricity, because it can kill you.

    Part of my job is EPA/DEP safety compliance per State contract specifications. The State of CT requires twist-lock grounded plugs & ground-fault interuptors for all power tools, pumps, & motors used @ a State job site. The reason this is written into the specs? Well, never assume a ground will save you.
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