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Title: PSU Gurus needed! Please check if my values make sense :) Post by: llamabucket on February 28, 2014, 11:17:49 PM Hey everyone,
I'm still on my quest to figure out why my rigs are shutting down and after lot's of testing and measuring today, I think I've come to the conclusion that my power supplies are NOT the issue. So in order for me to confirm this, I ask the help of you power supply gurus who know your current/voltage etc.. very well. 5x 280X card rig is split up between two HX850 (Gold Plus) power supplies. So I've got 850*2= 1700W to work with! Now, the way I understand it is that IF the power supplies are running at full load, the gold plus rating means that they are 87% efficient. The whole rig measures ~1550W at the wall -> 1550W*0.87 = 1349W supplied TOTAL to the components. PSU #1 (two cards, mobo/cpu/hd, all risers) measures ~888W at the wall -> 888*0.87 = 773W TOTAL to components connected to PSU 1 PSU #2 (three cards) measures ~650W at the wall -> 650*0.87 = 565W TOTAL supplied to the last three cards on PSU 2. Seeing 773W and 565W going to either PSU tells me that I'm way below the rated 850W, so I should be fine? Am I correctly calculating all of this? If someone could verify and let me know, I'd greatly appreciate it. If that is the case then I'm still baffled and confused why my rigs randomly turn off and I have to reset them after a day, a couple days, or even a couple weeks of mining? Thoughts? Thank you! :) llama Title: Re: PSU Gurus needed! Please check if my values make sense :) Post by: evansearle42 on March 01, 2014, 12:41:09 AM Should be good enough but the 773 watt psu might not last long..
Title: Re: PSU Gurus needed! Please check if my values make sense :) Post by: llamabucket on March 01, 2014, 01:04:12 AM Thank you!
I do agree that PSU #1 running 888W at the wall and 773W to the components is close to 850W. So i've gone ahead and undervolted the cards to 1137mV and I'm testing. I'm happy to say that PSU #1 is now running at ~800W at the wall, which would make it 696W to the two cards, mobo, risers. Does that sound better? Should I move some risers to the other PSU? I'm just afraid of problems involved with that. Also, do you think it's possible that by overloading PSU#1...it could have killed PSU#2? |