Is this PSU wattage too low?

Discussion in 'hardware' started by ohblu, Nov 30, 2010.

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  1. ohblu

    ohblu Registered Member

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    I'm looking at these HP desktops (for a relative): HPE-410t, HPE-450t, and p6680t. They are all basically the same. Unfortunately, they all have 300 watt PSUs, which I think is too low. A few of the reviews of the HPE-450t claim the PSU died on them after a short time.

    Here is what my relative wants in the computer (We're mainly interested in the HPE-410t):
    Windows 7 Home Premium
    Intel i5 760 quad core processor
    6 or 8 GB DDR3 RAM
    1 TB 7200rpm SATA hard drive
    500 GB 7200rpm SATA hard drive
    LightScribe 16X max. DVD+/-R/RW SuperMulti drive
    16x max. DVD ROM drive
    ATI Radeon HD 5450 512 MB or 512MB NVIDIA GeForce 315 graphics card
    Wireless-N LAN card
    integrated ethernet port
    15-in-1 memory card reader, 2 front USB 2.0 ports, 1394
    4 rear USB 2.0 ports
    Integrated sound

    I'm not sure if it matters but an All-in-one printer/scanner/copier will be connected to it. A USB backup hard drive may also be used every once in a while.

    Will a 300 watt PSU support all of this?

    The idea here is to buy a computer (for less than $950) that will still be powerful enough 10 years from now without having to upgrade. That's what I did when I bought my computer about 10 years ago. I only need to add a minimum of 512 RAM to my computer for it to work well enough to meet my needs now and I really don't even need that.
     
  2. wrongway67

    wrongway67 Registered Member

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  3. Noob

    Noob Registered Member

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    It will support it without any issues.
    According to the info i gathered the Core i5 760 only consumes 95W at full load and the HD 5450 uses around 20W at full load (This 2 are the hardware that uses most of the energy). Totaling 115W, leaving around 185W of usable energy for the other components.
    In theory, all the other hardware wouldn't be capable of using the rest, maybe the total system would use around 200-250W which would still leave room for tweaks or upgrades :D

    And that's considering you would run your PC at 100% LOAD ALL THE TIME, which is TOTALLY FALSE, you rarely use that much power, unless hardcore gaming of course :D
     
  4. ohblu

    ohblu Registered Member

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    Before my original post I tried three different power supply calculators and I got different results. Two of them indicated that the computer would use something like 295 watts to 318 watts. The Enermax power supply calculator is giving out numbers above 395 watts. The power supply that comes in these computers is 300 watts. So I don't even know what to make of all this.
     
  5. Noob

    Noob Registered Member

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    Don't believe them, if you want to really calculate it by yourself you can do like i did. search for the hardware specifications.
    I would say my guess is pretty much spot on :D
    And remember that is calculated with the MAX Wattage each component can use, which in real world, rarely happens unless gaming :D
     
  6. Bill_Bright

    Bill_Bright Registered Member

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    Noob is right, your 300W supply should be fine - in theory.

    First off, a major PC maker is not going to put in a component that does not support the system. They lose money if they have to replace anything under warranty.

    BUT - the problem is, the PSU is one area where PC makers try to cut costs. So most makers do not put in the best quality PSU they can find and that is too bad because IMO, you need to feed your sensitive, high-speed, digitial electronics clean, stable power to ensure a long life. Also, PSU makers tend to put their better quality components and features into their higher wattage offerings. So it is not likely your OEM PSU will run much better than at 70% efficiency, and it may still leave much of the "cleaning up" of the voltages to the motherboard board regulators. Now the motherboard regulators are designed to handle that, but the more work they have to do, the more heat they generate.

    Also, should you decide to upgrade your graphics card or CPU in the future, that 300W supply may not have enough horsepower (current on the +12V rail) to support it.

    So, technically, you will be fine with that 300W, but if me, I would plan on replacing it soon. Then you can use the 300W as a spare, or for testing fans.
     
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