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Pci x16 express slot's power to video card

Hello,
I am wondering why my new video card is asking for a 300 watt power supply when i read that the PCI x 16 express slot only delivers 75 watts?

the Slot is the only source of power for this card.

Will this damage my mother board?

thank you
6 answers Last reply Best Answer
More about express slot power video card
  1. That's 300w (at least) for the entire system.
  2. Thank you Jaguarskx: yes I see. Please forgive my ignorance, but if 75 watts is designed for the PCI slot, and is expected, why would one card ask for 300, and another for 400 watts?

    Just trying to understand and learn, I should not need to increase mine (card requires pc at 300/ I have 300) but might just for the heck of it.

    Thank you for your response
    I am just an old dog trying to learn new tricks lol
  3. Best answer
    howard664 said:
    Thank you Jaguarskx: yes I see. Please forgive my ignorance, but if 75 watts is designed for the PCI slot, and is expected, why would one card ask for 300, and another for 400 watts?

    Just trying to understand and learn, I should not need to increase mine (card requires pc at 300/ I have 300) but might just for the heck of it.

    Thank you for your response
    I am just an old dog trying to learn new tricks lol


    the 300w or 400w recommendation is just that a recommendation made by the video card maker to supply you with info on the approximate system needs for a system running that video card -- It will vary depending on how cautious the company is and how old the recommendations are - since there are a number of variables -- for example does the system use a 45w sempron or a 125w Phenom II CPU ? How many Ram Modules is the system using? How many HDDs and DVD drives? How many USB devices are getting powered ? How close to the rated Spec does the PSU actually perform (some cheap makes overstate the output by testing in a refridgerated room since cooler temps allow more output) ? etc.etc. -- so the GPU maker has to provide some sort of recommendation on what size PSU is needed but there are a lot of variables that will determine if your system needs more or less than that recommendation -- and to be safe you normally want to exceed that amount since PSUs will perform more efficiently and also last longer if you only use around 50-60% of its capacity since as units age the overall output declines and the closer to the max you are pushing it the faster the parts degrade.
  4. Thank you, these posts help. :)


    JDFan said:
    the 300w or 400w recommendation is just that a recommendation made by the video card maker to supply you with info on the approximate system needs for a system running that video card -- It will vary depending on how cautious the company is and how old the recommendations are - since there are a number of variables -- for example does the system use a 45w sempron or a 125w Phenom II CPU ? How many Ram Modules is the system using? How many HDDs and DVD drives? How many USB devices are getting powered ? How close to the rated Spec does the PSU actually perform (some cheap makes overstate the output by testing in a refridgerated room since cooler temps allow more output) ? etc.etc. -- so the GPU maker has to provide some sort of recommendation on what size PSU is needed but there are a lot of variables that will determine if your system needs more or less than that recommendation -- and to be safe you normally want to exceed that amount since PSUs will perform more efficiently and also last longer if you only use around 50-60% of its capacity since as units age the overall output declines and the closer to the max you are pushing it the faster the parts degrade.
  5. Best answer selected by howard664.
  6. This topic has been closed by Mousemonkey
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