Bitcoin Forum

so, i just got two BFL singles. based on my research a 500w PC power supply should be enough, so i got one and plugged it in. one BFL single works fine. but the other... well, firstly i had to buy two molex to 6 pin PCIe adapters, so there's that... but when i try to power them both and start mining through BFG, they work for a couple seconds, then the PSU shuts down. i assume due to too much power being used.

i don't have a kill-a-watt or other test stuff handy to determine what they're actually drawing.

i'm also fully aware they won't make any money, so skip it. not why i'm doing it.

how much juice do i need here? 600 watts? more? adapters a bad idea?

What power supply are you using?  I'll bet not all of the 500W goes to the +12V rail(s)...  2 BFL singles will run between 500 to 600 watts.

Cheapest frys had.. Lepa n500? https://www.google.com/shopping/product/16992540431297550423?lsf=seller:6136318,store:1052462545725638165&prds=oid:9891764564465420450&q=lepa+n500&hl=en-US&ei=F8kMWpjOD8LPmwGfjJHYAQ&lsft=gclid:CjwKCAiA6K_QBRA8EiwASvtjZRTCE4deoVCiCdgsE_1Xo7i1gDQTRsy40-fEqQnaQ-3DTZZSC97yUBoCQ9sQAvD_BwE

There's your problem right there...  Only get 34A out of the +12 rail for a whopping 408W!  ::)

  Specifications
 
Model Number: N500-SA
AC Input Voltage   
115/230V 47-63Hz
AC Input Current   8/5A
DC Output   +3.3V   25A   130W
+5V   20A   100
+12V   34A   408
-12V   0.8A   9.6W
+5Vsb   3A   15W
Total Power   500W
 

And that's a common miss by many, the total wattage out of an ATX PSU will be spread among various voltages as you can see.

Figures. Thanks. Off to the store...

Yeah, when it comes to mining it's better to leave atx psu away and only buy server grade psus.

I'll keep that in mind when I return this later.