Xfx 4870 wont boot with two power cables plugged in

I just build myself a new system, and was mortified when I saw that the psu I bought only had one pcie power cable and my shiny new xfx 4870 1 gb needed two! I thought I'd give it a try anyway, and the system did boot. It was at this point I found the molex to pcie adaptors in my case, so I took an adaptor, plugged on two different molex cables. Now the graphics card wouldn't work - the fan seemed to be running but at much lower speed than before, and nothing on the screen. When I took out the extra power the card ran again. I tried all sorts of different combinations with the adaptors, but the card would only run if only one power source was plugged in. What should I think of all this? I read a review of a4870 card somewhere where they had the same problem but it performed well nonetheless.
5 answers Last reply
More about 4870 wont boot power cables plugged
  1. your psu doesn't have enough amps to run this card
  2. Really? I figured 600W would be sufficient... so what should I aim for?
  3. as ubernoobie said the amps might not enough. the PSU may rated as 600w but if the amps are not strong enough it may face problems to power up the card
  4. On the side of your Power Supply Unit, there should be an electric rating label.

    There should be a +12V rating on the label.

    For example, +12V could be represented as 26 Amperes.

    I strongly suggest that you find out the ampere reading and tell me the answer.

    Perhaps your Power Supply Unit is not feeding enough power to your 4870.
  5. It says 28 amps... I guess that wont cut it after looking around on the net. My PSU is a LC6600 super silent. I guess I have to replace it. Will a corsair VX550W do the trick?
Ask a new question

Read More

Radeon Boot Power Cable Graphics