HD 6870 + Antec CX430w PSU - Power Requirements

somurray

I have recently built a PC containing:

G530
H61 Motherboard
4GB ddr3 memory
Sapphire 6870
Antec CX430
7200rpm HDD
DVD Drive

Rather foolishly, I bought a 430w PSU for a graphics card that AMD states needs a 500w minimum PSU. I used one of those PSU calculators and it seemed the system would run on that Antec 430w PSU.

When I turn on the PC with the two 75W 6-pin PCI Express® power connectors connected it does not work, but when I do not plug in the power connectors into the 6870, the PC powers on.

Is it the PSU at fault and should I get a PSU that is 500w?:( Feeling a bit stupid at the moment.

Eboggles

No it should run fine on a 430 watt, I'm pretty sure it's a Corsair, not an Antec.

Have you got it seated correctly? Connectors are secured?

What exactly happens when you plug in the PCIe connectors and power up the computer?

somurray

Hello Eboggles! Appreciate the help and speedy reply!

Sorry, you're right, it is the Corsair CX430w PSU.

It seems to have only one PCI-E 6-pin & 8-pin. When I just plug that in, the PC powers on, including the video card (then again, the video card's fan spins even when running on the motherboard alone for power). I hope only one PCI-E is enough.

The video card seated properly? Yes.

somurray

But when I plug in BOTH the PCI-E 6-pin AND 8-pin into the video card, it does not boot up whatsoever.

somurray

Should I buy this to change the 8 pin connector to a 6 pin? That appears to be the problem, the PC starts up with either just the 6 pin connected or none of them connected.

http://www.amazon.co.uk/Startech-Express-Power-Adapter-Cable/dp/B001TK3TJY/ref=sr_1_1?ie=UTF8&qid=1342048472&sr=8-1

Eboggles

After looking on the Corsair website, it only looks like there's one 6 pin Pci express connector..

The only thing I could think of (not trying to sound harsh) is that you've tried to put the CPU 8 pin connector in the 6870?

If you really need one I have a spare molex to six pin connector I could post to you.

I couldn't see why a 430 watt entry-level PSU would have a 6 pin and 8 pin connector, that's for something like a 7970!

somurray

Eboggles wrote: »

After looking on the Corsair website, it only looks like there's one 6 pin Pci express connector..

The only thing I could think of (not trying to sound harsh) is that you've tried to put the CPU 8 pin connector in the 6870?

If you really need one I have a spare molex to six pin connector I could post to you.

I couldn't see why a 430 watt entry-level PSU would have a 6 pin and 8 pin connector, that's for something like a 7970!

Not harsh at all, that is what, I, a big spa that I am, exactly did!:o

That's a very kind offer, Eboggles, I'll give you a PM.

Yeah, pretty bad connector selection for a budget PSU! :rolleyes:

Eboggles

There is probably one in the graphics card box, by the way. They normally supply a few, along with cables and the such.

somurray

Eboggles, you're a legend, you're right, there is a molex to 6 pin cable in the Sapphire box! Tried it now and it works!:D

Don't worry about sending me a spare molex to 6 pin adaptor, thanks for the offer anyway!

Eboggles

somurray wrote: »

Eboggles, you're a legend, you're right, there is a molex to 6 pin cable in the Sapphire box! Tried it now and it works!:D

Don't worry about sending me a spare molex to 6 pin adaptor, thanks for the offer anyway!

Glad you got it sorted .