Two 6950 1GB Cards for BitCoin, OK?

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XacTactX

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Rosewill Green 700 watt PSU

Build by ATNG, 700 watts, 54A on single 12V rail (not 100% sure about number of rails), two PCIe connectors (will adapt two Molex)

Total = 432 watts

Two (2) XFX 6950 1GB = 340 watts
MoBo = 15 watts (guessing)
i5 750 stock (idle) = 15 watts
4GB DDR3 = 10 watts (guessing)
HDD = 10 watts
ODD = 20 watts (guessing)
4 fans = 12 watts
Case = 10 watts (guessing)

Anyone have any reservations about me implementing this setup? Thank you, I appreciate your assessment.
 
I have a question about using Molex to PCIe power adapters. I see that some adapters have two Molex connectors going to a 6 pin PCIe or an 8 pin PCIe, and some have one Molex going to a 6 pin PCIe. So there are situations where you can either have one or two Molex to a 6 pin PCIe. Is there any increase in current stability for using two Molex instead of one to go to a 6 pin connector?

dinlee23 said:
it should be enough i dont see any problems in your setup...
Click to expand...

Thanks, I reached the same conclusion. Not even 70% of rated output.
 
Supposedly there is an increase in stability, as each connector is loaded less, but that only really happens when you use two separate molex lines. I doubt in actuality there is any real noticeable difference with good quality power supplies.

However, I would not trust Rosewill power supplies, go with a HX650 or TX650. Or a XFX 650 watt. If you want overclocking headroom or just want a buffer zone, go with a 750 watt, like the TX 750 V2.
 
XacTactX said:
I have a question about using Molex to PCIe power adapters. I see that some adapters have two Molex connectors going to a 6 pin PCIe or an 8 pin PCIe, and some have one Molex going to a 6 pin PCIe. So there are situations where you can either have one or two Molex to a 6 pin PCIe. Is there any increase in current stability for using two Molex instead of one to go to a 6 pin connector?
Click to expand...
Increase in stability? Not really. Increase in safety? Yes. A 6-pin PCI-E connector is supposed to have at least two +12V conductors, preferably three. A single 4-pin molex connector has one. I think you can figure out on your own what the better choice is.
 
IIRC a 6-pin PCIe connector is supposed to supply* up to 75W while an 8 pin is supposed to supply up to 150W. Converting these power figures to currents we get 6.25A and 12.5A respectively. I would not be at all surprised if overclocked graphics cards can draw more than this.

12.5A is more than I would want to see put down a single 12V wire of the size typically used in PCs. 6.25A is probablly ok but still pushing things a bit if the wires are long.

* The physical connector is specced for much more than this, this is apparently a rating from the PCIe guys.
 
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