Safe to use 4 pin to 8 pin 12v connector with Phenom II X6 1055T?

[Penoir]

I just bought the components for my new system which will be using a Phenom II X6 1055T processor which is rated to draw 125 watts. I have purchased all new components for the system, but am planning on using my old power supply (an FSP Blue Storm 500w). I only plan on running the system with onboard video, so the power draw will be far under the power supplies capacity, but I was wondering if I could just use an adapter that combines the 4 pin 12v connector and a molex connector to feed the 8 pin 12v on the motherboard for the CPU. I've also read that its ok to just run the 4 pin by itself, but I figured I'll probably need all 8 for my CPU. If the power were to be insufficient, what is the worst that could happen? could it fry anything by trying to draw too much power from the one 4 pin, or would it simply not boot?

Thanks. I was considering just getting the OCZ Fatal1ty 550w modular PSU, but $70 is a lot to spend if I'm just worrying about nothing.

 

[OVerLoRDI]

When I was in your situation I bought a 4 pin to 8 pin adapter. Worked fine as long as your PSU has enough juice, which it should. Just double check what the input voltage is on that CPU plug and check that voltage rail on your PSU.

 

[Penoir]

Ok, good. Thanks.

What would be the worst that would happen if it weren't enough power, or if I ended up only connecting the 4 pin without an adapter? Could it damage anything or would it just be unstable? (adapter might take another day to arrive, and i need to get this running asap to finish some work)

 

[SparkyJJO]

It would probably work OK. Heck back in the s939 days, I overclocked my opteron 165 to where it was estimated to pull nearly 180W, all through the 4 pin connector. And I ran it at full load a lot.

 

[Penoir]

Ok, great. Thanks a lot. I'll probably avoid overclocking for now until I find it's stable and can see if I even need to overclock it. Thanks for the reassurances. I can't wait to have this thing running. It's a huge upgrade from my Athlon 64 3000+.

 

[SparkyJJO]

The adapter would be the safest. That way, if it was to burn a connector, it would burn the one at the adapter/PSU junction, not at the motherboard. Just something else that came to mind.

 

[Blastman]

According to both these references ...

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... a 4 pin ATX 12v (or EPS) connector is rated 8A per pin. This means 8A x 2 x 12v = 192 watts.

Since your CPU will draw some power from the 24 pin ATX connector, you should be under 125W draw from the 4-pin ATX 12v. Engineers are usually conservative, so you should have power to spare even if only using a 4-pin connector rather than the 8-pin one given a 125W rating for the processor.

Heavy overclocking can increase the power draw substantially (with overvolting), so if you're going to peddle to the metal overclock you might want an 8-pin EPS connector.