Multiple PS for Mining Rig

[edge929]

I know this topic has been discussed before but I could not find any solid answers.

For those of us who are the family (and their friends) PC doctor, we have a ton of old parts lying around, including various power supplies. I was able to get a couple of 290's for $400 before they shot through the roof in price and wanted to use my old HTPC (AM3 build) for a mining rig. The only part I don't already have on hand is a single PS to power them. I do however, have many 300-350 watt power supplies lying around. If I dedicate one PS to each GPU and another to the rest of the rig, would this hurt anything?

I'm already familiar with rigging up the ATX connector for turning it on and would turn both supplies to GPUs on just prior to turning the main rig on. A 290 at full load, stock settings is roughly consuming 260W of power. I don't see why this wouldn't work. Am I missing anything?

 

[Core32]

Only issue I see is what portion of the 300-350W is dedicated to the main rail.
That might not be enough individually to supply proper power.

 

[edge929]

Yeah, that was my only concern as well. These being older power supplies I would assume they just have a single rail but will look up the model numbers to confirm. I think the biggest con to using 3 power supplies is power consumption. None of them will be 80 Plus certified, let alone Gold or Platinum. Over a year of mining a single, new ~800W 80 Plus Gold would probably pay for itself.

 

[Ultima99]

A single 25A 12v rail should do it.

 

[mkrohn]

Yeah, that was my only concern as well. These being older power supplies I would assume they just have a single rail but will look up the model numbers to confirm. I think the biggest con to using 3 power supplies is power consumption. None of them will be 80 Plus certified, let alone Gold or Platinum. Over a year of mining a single, new ~800W 80 Plus Gold would probably pay for itself.

Find the thread called cheap power that is in this forum and just buy a dell server PSU and call it good

 

[pgaster]

This might do the trick for you: http://www.add2psu.com/store/

 

[mkrohn]

This might do the trick for you: http://www.add2psu.com/store/

he said he is aware of that.... doesn't take much to just run 2 wires though

 

[edge929]

he said he is aware of that.... doesn't take much to just run 2 wires though

Yeah, I rigged up some water-cooling gear in it's own ATX case, used an old 250W power supply, hooked up a cheap swtich to the mobo connector with 2 wires, slapped some electrical tape on them, done.

I have a Kill-a-watt on the way to get a more accurate picture of power consumption. I'm going to use my HX750 to see if it's enough juice for two 290s running at stock volts. Mobo, 45W CPU, 3.5" HDD and the 290s, nothing else.

 

[mkrohn]

Yeah, I rigged up some water-cooling gear in it's own ATX case, used an old 250W power supply, hooked up a cheap swtich to the mobo connector with 2 wires, slapped some electrical tape on them, done.

I have a Kill-a-watt on the way to get a more accurate picture of power consumption. I'm going to use my HX750 to see if it's enough juice for two 290s running at stock volts. Mobo, 45W CPU, 3.5" HDD and the 290s, nothing else.

my HX750 seems to be about its limit with a pair of OC 280x's which are about the same as a 290 in power consumption but will run them. I undervolted them to buy some extra room with that unit though.