Need help with Power Supply wattage requirement

Hello -
Thanks for reading.

I am trying to figure out whether I should buy a new power supply or use the one I have for a new build.

The new build will have the following specs:

Processor: i7 2700k
Motherboard: Gigabyte Z68X-UD3H-D3
Memory: 16 GB
Optical Drive: Liteon Bluray 12x writer
Graphics: AMD Radeon™ HD 6570 Graphics
SSD: 1 drive [120 GB]
HDD: 2 drives [1TB 5600 RPM, 512 GB 5600 RPM]

I have a 500W PSU from Cooler Master. I recently went to Microcenter and the tech told me that I need a minimum of 550W PSU (suggested a 600W PSU from Thermaltake) and the 500W PSU I have will not be enough.

I used the Newegg power supply calculator gave me a rating of 361W which is much less than the 500W that I have. Can someone tell me if I can use the 500W PSU or was the tech actually correct in saying that I need a minimum of 550W (the supposed formula was NewEgg value + 200W). If the 500W is enough, I would like to use it so I can reduce creating more electronic junk in the world.

8 answers Last reply Best Answer
More about need power supply wattage requirement
  1. You should be fine for now. I'd personally drop $40-$50 on a 600w PSU, but I'm a paranoid with my PCs. If you add anything to it (another HDD or anything like that)I would definatly get a bigger PSU.
  2. If you are paranoid with your computers you would know better than to buy $40 600w power get what you pay for.

    With an HD6570 you can get by with a quality 400w power supply. Since Coolermaster tends to be crap you are fine with the 500w model you have.

    Either the Microcenter tech was an idiot or he was trying to make a commission off selling you that Thermaltake power supply or both. If anything Thermaltake is even worse than Coolermaster.

    So keep what you have now. If you ever upgrade to a decently powerful video card you will need to upgrade though. Stick with Corsair, Seasonic, PC Power and Cooling, XFX, Silverstone, Enermax, OCZ, and Antec for quality brands.
  3. Yes it will work fine with your setup, it will hardly ever go over 250watt load! (Newegg's calc over estimates)
  4. For future upgrades, at least a minimum of 700 Watts. I'm using a OCZ Modxstream Pro 700 watts 80 plus certified(modular).
  5. Best answer
    aqe040466 said:
    For future upgrades, at least a minimum of 700 Watts. I'm using a OCZ Modxstream Pro 700 watts 80 plus certified(modular).

    And your video card draws 80 watts only need a 400-450w power supply.,3135.html

    You can run a $500 GTX 580 with a quality 550w power supply.
  6. Thanks everyone. I decided to stick with what I have for now.

    My windows rating is now 6.8(mostly due to low end graphics card)

    My memory is crucial ballistix 16 GB. Why is it rated 7.8?
    Also why is the i7 2700K rated at 7.8?

    Did I screw up the setup?

  7. WEI is a useless benchmark. 7.9 is a high as it goes. My 2600K at 4.5Ghz also scores a 7.8 and my 8GB of DDR3 1600 does as well.
  8. Best answer selected by pvamsik.
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