Power Supply - How many watts do i need

HD7850 Sapphire
i7 4770 Haswell Intel
8GB RAM
Windows 8.1
12 answers Last reply
More about power supply watts
  1. You don't need more than 300w. But I recommend going higher if you're going to upgrade or Crossfire later on.
  2. Hd 7850
    System in IDLE = 160W
    System Wattage with GPU in FULL LOAD = 256W

    Intel 4770
    System in IDLE = 39W
    System Wattage with CPU in FULL LOAD = 135W

    TOTAL:391W/32A

    around 500-550 watt should do it
  3. Modern, why are you counting the system wattage twice? My 7950 which uses a lot more power then the 7850 in a normal system draws between 300-325W. I don't see how you can get 391W.

    The 7850 is a 130W card/part. 4770 is 84W? Lets say 100W. That's 230W for the two biggest draws of 12V power. No way that system at stock setting draws more then 300W, which agrees with what TechCIDLC said above. As he also said you only need more if you are planning on OCing or running CF later on. I'm running my 7950 on a Rosewill Capstone 450W. Its cheap and would have zero issues running a single 7850. You might want to buy the 500W if you'll be doing CF.
  4. But here is the problem,

    I had a computer with a old i5 card and 4gb ram and hd7850

    but a week ago i bought a new computer with i7 4770
    8GB RAM and a gtx650

    i want to remove the gtx650 from the new computer and place my old hd7850
    But when i do that and i connect the 6 pin to the hd7850 and when i starting up it gives 1 long and 2 short beeps
    I connect it with a power supply of 500Watts how is this possible

    the hd7850 card works very well on my old computer i test it a hour ago
    :(
  5. 4745454b said:
    Modern, why are you counting the system wattage twice? My 7950 which uses a lot more power then the 7850 in a normal system draws between 300-325W. I don't see how you can get 391W.

    The 7850 is a 130W card/part. 4770 is 84W? Lets say 100W. That's 230W for the two biggest draws of 12V power. No way that system at stock setting draws more then 300W, which agrees with what TechCIDLC said above. As he also said you only need more if you are planning on OCing or running CF later on. I'm running my 7950 on a Rosewill Capstone 450W. Its cheap and would have zero issues running a single 7850. You might want to buy the 500W if you'll be doing CF.


    oh man sorry i feel like an idiot. it turns out the 7850 is 106watts and the 4770 is 84watts.
  6. What "500W" PSU is it? Can you swap PSUs as well as the cards?
  7. its a A85 Chieftec 500W power supply, you can swap the card en PSU
  8. i smell a chiefcheap psu.
  9. Chieftec is evil. They design their PSUs so that in a few months it travels to the Void and takes all of your other components with it, too.
  10. What kind of PSU do you guy recommend for me, i can spend around the 60 - 80 euro's
  11. Here's a very reliable PSU: EVGA's SuperNOVA 80+ Gold @ 750W (Fully Modular)

    http://pcpartpicker.com/mr/amazon/evga-power-supply-120pg0750gr
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